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2006 Section 5 - Brakes.indd - Oemys

1. 39 PARK BRAKE SYSTEM 65 Brake Pad 2 39 Lever Actuated Park Brake System Components 66 Brake Pad Replacement Brembo 52mm Caliper 39 Automatic Apply Park Brake System Components 66 Brake Pad Replacement Brembo 68mm Caliper 43 J72 Park Brake Description 66 Brake Pad Replacement Bosch ZOH T Caliper 44 Actuator Assembly e cei 70 Brake Pad Replacement PARK BRAKE SYSTEM DIAGNOSIS 72 Meritor Quadraulic Callper 5 3 5 3 5 45 Park Brake Does Not GIG 72 Bleed Screw 46 Park Brake Will Not 73 Seal and Dust Boot Replacement COMPONENT REPLACEMENT J72 Park Brake 74 Brembo 52mm Caliper erret 46 Park Brake Assembly 74 Seal and Dust Boot Replacement Park Brake Actuator Assembly Replacement 15 Brembo 68mm 49 Park Brake System 76 Seal and Dust Boot Replacement Park Brake System ChecKk eren 76 Bosch ZOH
2. 9 Excessive Pedal ENDE 26 MEC Ce TT 10 Pedal Pulsation Brake Roughness or Chatter Basic Operation of Hydro Max Booster Assembly Leaky 27 and Master Cylinder nrc 12 No Braking Effect or Excessive Pedal Travel 27 Hydraulic Fluids esent 16 NANET Suicide ai Brake Fluid Tubing Hoses and 16 prake Didgnosis SG ha plfig 28 Booster Fluid Tubing Hoses and Fittings e 16 Brake Noise Diagnosis RR 28 Booster Fluid Source sssssses 17 Brake Noise Diagnosis 28 Pedal Stop and Proper Spring Load 17 Brake Noise Diagnosis Squeal 28 H aro Nast Brake BRAKE ROTORS 28 Hydro Boost Hydraulic Brake 18 Hub and Rotor Assemblies 28 System Description 18 Brake Calipers and 65 29 Master Cylinder 18 Brake Rotor Thickness Variation 29 Reservoir and Cover 18 Brake Rotor Lateral Runout 29 Power Steering
3. 18 Brake Rotor Tolerance 30 Power Piston and 19 Bosch Hydraulic Brake 30 Brake Fluid and Brake Fluid Handling 22 vanning LONTANA E uar Ar DO CIT Substandard Or Contaminated Brake Fluid 22 Booster Backup Pump Rung 94 Flushing the Brake Hydraulic 23 31 Normal Operation 23 Brake Pedal Feels Spongy Soft or Springy 31 BRAKE SYSTEM TESTING 24 Braka Fedal Feels Very Mand 31 External Conditions that Affect Brake Performance 24 Potential Master Cylinder and Booster Leak Points 31 4 32 WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual W Series Chassis SECTION 9 3 Brakes Antilock Brake System ABS Diagnostics 32 Caliper Piston Replacement MAINTENANCE AND 32 Meritor Quadraulic 58 Setup lt
4. 32 Caliper Guide Pin and Dust Boot Replacement Brake Actuation Linkage Bell Crank Service 33 52MM CAPET 60 Caliper Replacement Brembo 52mM Caliper 34 Caliper Guide Pin and Dust Boot Replacement Caliper Removal Brembo 52mm 34 stu Caliper lt lt 60 Caliper Installation Brembo 52mm 34 Guide Pin and Boot Replacement Caliper Replacement Brembo 68mm Caliper 39 BOSCH ZOH T Caliper 61 Caliper Removal Brembo 68mm Caliper 35 Caliper Mounting Bolt Replacement 62 Caliper Installation Brembo 68mm Caliper 35 Brake Rotor 62 Brake Caliper Replacement Bosch ZOH T Caliper 36 Brake Rotor 62 Brake Caliper 36 Brake Rotor 62 Brake Caliper IriStallatlor s nore rns 37 Refinishing Brake Rotors ranae acc ctor 63 Brake Caliper Burnishing the Rotors and Pads 65 Meritor Quadraulic
5. 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual TOC Blink Code 33 SECTION SAE Fault Code SID 4 FMI 1 Description Right Rear Wheel Sensor Air Gap Too Large The ABS ECU has detected that the output voltage signal of the wheel sensor is too low Check for loose wheel bearings or excessive hub run out Push the wheel sensor all the way in until it contacts the tooth wheel Do not pry or push sensors with sharp objects Sensors will self adjust during wheel rotation To check the amplitude with a voltmeter disconnect the X3 connector from the ECU and measure across pins 7 and 6 Blink Code 34 SAE Fault Code SID 3 FMI 1 Description Left Rear Wheel Sensor Air Gap Too Large The ABS ECU has detected that the output voltage signal of the wheel sensor is too low Check for loose wheel bearings or excessive hub run out Push the wheel sensor all the way in until it contacts the tooth wheel Do not pry or push sensors with sharp objects Sensors will self adjust during wheel rotation To check the amplitude with a voltmeter disconnect the X3 connector from the ECU and measure across pins 10 and 3 W Series Chassis 118 Brakes Blink Code 41 Fault Code SID 2 FMI 10 Description Right Front Wheel Sensor Speed Drop Out The ABS ECU has detected a temporary loss of wheel speed signal Adjust the air gap by pushing the sensor all the way until
6. NOTICE If the shaft cannot be completely removed due to inter ference with the body panels pull the shaft out as far as possible and complete steps 4 through 7 WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 TOC CALIPER REPLACEMENT BREMBO 52MM CALIPER Caliper Removal Brembo 52mm Caliper 1 Disconnect the brake hose fitting at the caliper Cap the fitting and tie the brake hose up and out of the way 2 Remove the two caliper bracket to steering knuckle mounting bolts Protective Covers Figure 5 11 Typical caliper mounting bolts 3 Remove the caliper by lifting it from the mounting bracket 4 Clean up any brake fluid that may have leaked out of the hose or caliper W Series Chassis 34 Clean Dry and Inspect Brembo 52mm Caliper Brakes CLEAN PARTS 1 Thoroughly clean the exterior caliper surfaces using a damp cloth DRY AND INSPECT PARTS 1 Use soft clean paper or cloth rags or compressed air to completely dry parts immediately after cleaning them 2 Carefully inspect each part for wear or damage 3 Repair or replace worn or damaged parts Caliper Installation Brembo 52mm Caliper 1 Install the caliper mounting bracket onto the steering knuckle 2 Install the two new caliper mounting bolts 3 Tighten the caliper mounting bolts to 172 N m 127 Ib ft 4 Remove the cap fro
7. 1 Use soft clean paper or cloth rags or compressed air to completely dry parts immediately after cleaning them 2 Inspect the dust boots for tears or other damage 3 Inspect the guide pin bores for wear or damage 4 Repair or replace worn or damaged parts Guide Pin and Boot Installation Brembo 68mm Caliper 1 Lubricate the following components with brake grease a Inside of the caliper guide pin bores b The outside of the caliper guide pins c The inside of the dust boots 2 Install the dust boots on their seats 3 Install the guide sleeves 4 Install the caliper Refer to Caliper Replacement Brembo 68mm Caliper CAUTION Be careful not to damage the boots when installing the caliper W Series Chassis 61 Brakes Guide Pin and Boot Replacement Bosch ZOH T Caliper Guide Pin and Boot Removal Bosch ZOH T Caliper 1 Remove the caliper Refer to Caliper Replacement Bosch ZOH T Caliper 2 Remove the caliper guide pin 3 Remove the dust boot Clean Dry and Inspect Bosch ZOH T Caliper CLEAN 1 Clean the caliper guide pin bore 2 Clean the dust boot DRY AND INSPECT 1 Use soft clean paper or cloth rags or compressed air to completely dry parts immediately after cleaning them 2 Inspect the dust boots for tears or other damage 3 Inspect the guide pin bores for wear or damage 4 Repair or replace worn or damaged parts Guide Pin and Boot Installation Bosch ZOH T Caliper
8. 2 Tighten the anchor pin mounting nut to 200 N m 148 Ib ft 3 Install the backing plate Install the backing plate mounting bolts and washers 5 Tighten the backing plate mounting bolts to 41 N m 30 Ib ft 6 Install the linings Refer to Park Brake Shoe Replacement 7 Install the drum Refer to Brake Drum Replacement 8 Adjust the parking brake Refer to Park Brake Cable Service Adjustment D PAGE W Series Chassis 84 Automatic Apply Park Brake Assembly Replacement Brakes Automatic Apply Park Brake Assembly Removal IMPORTANT Ensure the park brake is released before trying to remove it 1 Remove the propeller shaft Refer to Two Piece Propeller Shaft Replacement or Three Piece Propeller Shaft Replacement 2 Disconnect the hydraulic line from the parking brake assembly CAUTION Cap the end of the transmission in order to minimize fluid loss and prevent the entry of contaminants into the system 3 Remove the parking brake and yoke assembly mounting bolt and washer 4 Remove the parking brake and yoke assembly 5 Remove the yoke from the parking brake assembly 6 Inspect the yoke ears for damage and the splines for the following damage e Wear e Burrs e Twisting Automatic Apply Park Brake Assembly Installation NOTICE Refer to Fastener Notice in Cautions and Notices 1 Install the bolts and washers holding the yoke to the parking brake assembly 2 Tighten the
9. All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 7 Pump the brake pedal repeatedly to move the pistons out until the pads are pressed against the rotor Continue pumping the brake pedal until pedal force returns to normal and the normal stroke is restored 8 Have an assistant press and hold the brake pedal While the system is under pressure check all of the brake fittings lines and hoses for possible fluid leaks 9 Check the brake fluid level in the reservoir Add fluid if necessary Caliper Piston Replacement Bosch ZOH T Caliper Caliper Piston Removal Bosch ZOH T Caliper 1 Remove the caliper Refer to Caliper Replacement Bosch ZOH T Caliper 2 Loosen the bleed screw but do not remove it 3 Place one end of a hose on the tip of the bleed screw and the other end in a container to catch the brake fluid as it drains 4 Use disc brake pad spreader tool to press both pistons back into their bores which will force the brake fluid out of the caliper CAUTION While pressing the pistons back into their bores be careful to not damage the insulat ing ring and the dust covers The dust covers must not be twisted or allowed to trap air If air becomes trapped in the dust cover use a flat blade to gently lift the edge of the seal to release the air PAGE W Series Chassis 57 Brakes Do not place your fingers front of the pis ton in a
10. Brakes Do not let the brake master cylinder fluid get below the minimum level during the bleeding operation Keep the master cylinder reservoir filled with new DOT 3 brake fluid Failure to keep the brake reservoir level above minimum could result in more air entering system making it impossible to effectively bleed the system 6 Bleed the brake system Put a wrench on the brake actuator bleeder fitting Start with the farthest from the modulator typically the right rear then attach a length of clear plastic tubing to the bleeder fitting Make sure the tube fits snugly 7 Submerge the tubing in a container of clean brake fluid NOTICE Both the tubing and container must be able to withstand the effects of brake fluid 8 Depress the brake pedal 10 to 15 times using the maximum available stroke 9 Loosen the bleeder fitting until the fluid begins to flow about 3 4 turn while depressing the brake pedal through its maximum available stroke 10 Tighten the fitting firmly prior to releasing the brake pedal 11 Repeat Steps 6 through 8 several times until the discharged fluid is free of air bubbles 12 Repeat Steps 3 through 9 to bleed the remaining three brake actuators Bleed in sequence of the longest to the shortest circuit from the modulator 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION MEZ Yers 5
11. Brakes 13 Check the travel of the brake pedal If a firm resistance is felt the manual bleeding procedure is complete 14 Check the fluid level in reservoir and fill if required Replace reservoir cap and dispose of used brake fluid 15 Remove wheel chocks W Series Chassis 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION m 9 PAGE 107 Brakes W Series Chassis WABCO TOOLBOX User s Manual Meritor WABCO TOOLBOX Software is a PC based diagnostics program that runs in Windows 98 Me NT 2000 or XP TOOLBOX Software provides PC diagnostic capabilities for Meritor WABCO tractor and trailer pneumatic ABS hydraulic ABS and the electronic leveling module ELM for both tractor and trailer The program provides four basic functions Displays both constant e g ECU number and changing e g RPMs information from the system under test Displays both active and stored system faults as well as the appropriate repair instructions Provides a link to service information testing procedures etc ABS and HABS only Activates system components to verify system integrity correct component operation and installation wiring System Requirements Pentium based personal computer Microsoft Windows 98 Me 2000 or XP Internet Explorer version 3 02 or higher must be installed NOTICE You must have Administrator Privileges to
12. If you cannot find the cause with these tests refer to Brake System Diagnosis Visual Inspection Check for a cracked casting or brake fluid leaks around the master cylinder A leak will have at least one drop of fluid A damp condition is normal Check the pedal linkage for binding and for incorrect pushrod length Disassemble the master cylinder if no brake pedal binding or improper brake pedal travel is found Refer to Master Cylinder Overhaul Check the master cylinder for swollen or elongated primary piston seals If you find swollen seals refer to Brake Fluid and Brake Fluid Handling Inspect all pipes hoses and fittings for leaks at regular intervals The fittings must be tight All clips clamps and unions supporting the pipes and hoses must be securely in place Ensure that all hoses and tubes do not contact parts of the vehicle Wipe clean any area suspected of leaking Leaking fluid will then be easily seen If a leak is found tighten repair or replace nearby fittings and bolts GENERAL BRAKE SYSTEM DIAGNOSIS Excessive Pedal Effort Condition Suggested Correction Replace the pads Pads worn below minimum thickness specification Faded overheated condition glazed pads blued or heat checked rotors Replace the affected rotor and or reface the pads if sufficient brake lining remains Grease oil and or brake fluid on the brake linings Replace both
13. WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual INNER PISTON SEAL Figure 5 32 J72 Brake Piston Seals TOC SECTION W Series Chassis 69 Brakes Auto Apply Warning Lamp The auto apply warning lamp turns on when the system pressure falls below than 900 psi and the ECM receives the signal from the transmission Park Brake Warning Lamp The park brake warning lamp illuminates when system pressure falls below 900 PSI or when the parking brake pull button is pulled out Park Brake Pull Switch The park brake pull switch is mounted on the instrument panel This is a manual activation switch for the park brake This switch is normally closed pushed in The body manufacturer determines final location of this switch Park Brake Pump Motor Relay The park brake pump motor relay is located in the underhood fuse box on the front driver s side of the radiator core support It receives ground from the ECM and acts as the automatic control circuit for the high voltage current required to run the pump motor When the ECM supplies ground to the relay switch the contacts close to complete the feed circuit to the pump motor WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 5 The ignition relay is also located in the underhood fuse box on the front drive
14. WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual 5 1 Brakes 2006 BRAKE SYSTEMS WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Seies WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual 5 2 Brakes TOC TABLE OF CONTENTS MR 24 FASTENER TIGHTENING SPECIFICATIONG 6 Vehicle Loading 24 BRAKE SYSTEM 5 1 7 Front Wheel Bearings DERE 24 BRAKE LATHE SPECIFICATIONS AMMCO 7 Front End Alignment c ERE 25 BRAKE LATHE SPECIFICATIONS ACCU TURN VPE 7 Brake Fluid 25 INTRODUCTION iiis iaa 8 Prake OSS ANd Objectives Of This 8 DIAGNOSTICS AND TROUBLESHOOTING 26 Description and 8 Service Brake 5 26 SERVICE BRAKE SYSTEM DESCRIPTION 8 Master Cylinder Diagnosis Tm 26 Service Brake System 9 Brake Hose and Pipe Diagnosis 26 Master Cylinder Reservoir and Fluid Level Sensor 9 General Brake System Diagnosis X 26 Hydraulic Brake
15. 1 Lubricate the following components with brake grease a Inside of the caliper guide pins b The outside of the caliper guide pins c The inside of the dust boots 2 Install the dust boots on their seats 3 Install the guide sleeves 4 Install the caliper Refer to Caliper Replacement Bosch ZOH T Caliper 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 5 W Series Chassis TOC CALIPER MOUNTING BOLT REPLACEMENT CAUTION When the caliper mounting bolts are removed they MUST be replaced with new bolts Caliper Mounting Bolt Removal 1 Loosen and remove the caliper mounting bolts Caliper Mounting Bolt Installation 1 Install the new caliper mounting bolts 2 Tighten the caliper mounting bolt e The caliper mounting bolts on Brembo 52mm calipers are tightened to 34 N m 25 Ib ft The caliper mounting bolts on Brembo 68mm calipers are tightened to 115 N m 85 Ib ft The caliper mounting bolts on Bosch ZOH T calipers are tightened to 115 N m 85 Ib ft The caliper mounting bolts on Meritor Quadraulic calipers are tightened to 115 N m 85 Ib ft BRAKE ROTOR REPLACEMENT Brake Rotor Removal 1 Remove the brake caliper Refer to Brake Caliper Replacement Front or Brake Caliper Replacement Rear 2 Remove the hub and brake rotor assembly Refer to Wheel Hub Bearing and Seal Replac
16. 1 Remove the caliper assembly Refer to Brake Caliper Replacement Bosch ZOH T Caliper 2 Suspend the caliper 4 inspect for wear or damage Remove slippers Clean anchor plate abutments and install new slippers Inspect pins and pin boots for wear or damage If any damage or defects are found repair or replace as required Inspect the inside of the caliper assembly for signs of fluid leakage If any is found refer to Brake Caliper Overhaul Check machined surfaces of caliper If any rust or corrosion is present carefully clean surfaces with hand held wire brush Clean Dry and Inspect Bosch ZOH T Caliper 1 Clean away any corrosion from the machined surfaces of the steering knuckle and caliper with a wire brush Brake Pad Installation Bosch ZOH T Caliper NOTICE Make sure the brake hose is not twisted or kinked after installation Damage to the hose could result 1 2 Lubricate the caliper and anchor plate sliding surfaces with Silicone Lube P N 1801 0909 or the equivalent Position inner and outer pads over anchor plate slippers with lining material facing rotor 3 Align flat on upper top guide pin head and rotate caliper closed to align with the flat on caliper upper top guide pin boss Be careful when positioning caliper over the disc brake pads rotor and upper top guide pin head to avoid tearing cutting or dislodging piston boots or guide pin boots 4 Torque
17. Make sure the seals are properly seated before continuing 3 Lubricate the pistons around their outer diameter with brake grease 4 Install dust boot on the caliper 5 Install the pistons Refer to Caliper Piston Replacement Bosch ZOH T Caliper 6 Install the caliper Refer to Caliper Replacement Bosch ZOH T Caliper Brakes Seal and Dust Boot Replacement Meritor Quadraulic Caliper Seal and Dust Boot Removal Meritor Quadraulic Caliper 1 Remove the caliper Refer to Caliper Replacement Meritor Quadraulic Caliper 2 Remove the caliper pistons Refer to Caliper Piston Replacement Meritor Quadraulic Caliper 3 Remove the dust boots 4 Remove the seals Clean Dry and Inspect Meritor Quadraulic Caliper CLEAN PARTS For ground or polished parts CAUTION Do not use hot solution tanks or water and alkaline solutions to clean ground or pol ished parts Damage to parts will result WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual Use safety solvent or equivalent to clean the surfaces of ground or polished parts For rough metal parts Use a cleaning solvent or weak alkaline solution in a hot solution tank to clean rough metal parts If a hot solution tank is used follow the instructions below 1 Place the rough parts in the hot solution tank 2 Leave the rough parts in the tank until they ar
18. Reset Memorized This is an automatic default and cannot be de selected It indicates the ECU has memorized the installed retarder relay Once the ECU has seen a retarder it expects to see it every time the vehicle is powered up Because there are times when an ECU is moved to another vehicle or during diagnostic testing you may want the ECU to disregard this learned component Use the Reset Memorized command for this purpose WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 5 Figure 5 48 Reset Memorized Option Screen Select Component Tests from the Hydraulic ABS Main Menu Then select Reset Memorized from the pull down menu to reset the Learned Component screen Fault Information Screen The Fault Information Screen contains a description of the fault Repair instructions for each fault appear at the bottom of the screen Faults that occur after the screen is displayed will not appear until a screen update is requested Use the UPDATE button to refresh the fault information table After making the necessary repairs use the CLEAR FAULTS button to clear the fault Use the update button to refresh the fault information table and display the new list of faults W Series Chassis 93 Brakes Figure 5 49 Fault Screen ABS Indicator Lamp Activation To activate the ABS indicator lamp select HABS
19. Service Manual 5 CAUTION The park brake is NOT designed for dynamic stops if a dynamic stop occurs the park brake assembly must be inspected immedi ately for any internal damage Pressure Transducer The pressure transducer monitors the pressure of the system and relays that information back to the ECM The critical pressure values are the cut in and out for the motor which are 1200 psi and 1400 psi respectively PARK BRAKE SYSTEM DIAGNOSIS Park brake operational concerns fall into two different areas Brake Does Not Hold Brake Will Not Release Park Brake Does Not Hold To test the park brake function conduct the following steps 1 Choose a LEVEL location away from people pets and buildings 2 Ensure the vehicle is in PARK 3 Apply the service brake foot brake and start the engine 4 Place the transmission in DRIVE 5 Apply the park brake by pulling the park brake button out to the applied position W Series Chassis 72 6 Slowly release the service brake foot brake Brakes 4 0 If the vehicle moves reapply the foot brake and place the transmission back in PARK Service the park brake before repeating the test 7 f the vehicle does not move GRADUALLY increase the throttle opening to approximately 1 500 RPM for five seconds then release the throttle and apply the service brake foot brake Test results a If the brake holds no further action is re
20. The ABS unit has detected an open circuit between the pins that connect to the left front ABS outlet valve on the X1 connector 10 amp 2 The open circuit may be caused by a bad solenoid valve or an open in the cable sockets Use an ohmmeter to check the resistance and determine the bad component Blink Code 22 SAE Fault Code SID 48 FMI 6 Description Left Front Outlet Valve Shorted to Ground The ABS ECU has detected that the outlet solenoid valve X1 10 is shorted to ground Check the cables from the ECU to the valve for damage Blink Code 23 SAE Fault Code SID 45 FMI 3 Description Right Rear Inlet Valve Shorted to Battery Voltage The ABS ECU has detected that the inlet solenoid valve X1 6 is shorted to battery voltage Check the cables from the ECU to the valve for damage W Series Chassis 115 Brakes Blink Code 23 SAE Fault Code SID 45 FMI 5 Description Right Rear Inlet Valve Open The ABS unit has detected an open circuit between the pins that connect to the left front ABS inlet valve on the X1 connector pins 6 amp 2 The open circuit may be caused by a bad solenoid valve or an open in the cable sockets Use an ohmmeter to check the resistance and determine the bad component Blink Code 23 SAE Fault Code SID 45 FMI 6 Description Right Rear Inlet Valve Shorted to Ground The ABS ECU has detected that the inlet solenoid valve X1 6 is shorted to ground Check the cables from the ECU t
21. which diagnostic steps need to be taken The brake technician must have the necessary skills needed to perform each step The flow charts are structured to guide the brake technician to take the quickest and easiest steps first Often these first simple steps will be enough to determine what repair needs to be made In all cases the vehicle manufacturer s service manual must be used for any repair instructions Brake system warning lights and buzzers are unique to the vehicle manufacturer The Brake Warning Light and Buzzer Do Not Shut Off flow chart offered in this guide is generic and may not apply to all vehicles The vehicle manufacturer s service manual must be consulted in order to determine the proper function of these warning devices Exclusions The ABS portion of the hydraulic brake system is not addressed in detail in this guide since the ABS hardware and software are unique to the specific vehicle manufacturer Any diagnosis or repair needs to be done in accordance with the vehicle manufacturer s ABS service manual WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 5 The light buzzer come on together typically in response to signals from the parking brake switch booster flow switch master cylinder fluid level indicator switch the master cylinder differential pressure switch or booster backup pump Toc Warning Light
22. 19 Remove the seals from the caliper bores 20 Unscrew the bleeding screw 5 21 Clean carefully the caliper bores using suitable materials and products CAUTION Do not use products that could damage the seals such as perchloroethylene thinner gasoline etc Once removed the seals must not be re used but replaced with the new ones 22 Moisten the new seals and external diameter of the pistons with brake fluid Install the new seals in the seats inside the caliper body ensuring that they are perfectly positioned Moisten the pistons around their outer circumference using the brake fluid Insert the dust boots 14 on the pistons 12 see Fig 2T 23 24 25 WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual S 5 4 8 Brakes 34 Mount the pads in the caliper ensuring that the arrows are pointing in the correct direction Ensure that the friction surfaces do not become dirty with grease if necessary all traces of grease must be removed with sand paper Figure 27 Insert the dust boots on the piston 26 Moisten the dust boots fitting collar with brake fluid The pads must be inserted with the friction 27 Insert the dust boots in the bore of the caliper material facing the disc Incorrect positioning UD of the pads will affect braking performance 28 In
23. 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 EAM Brakes FLOW ENVITZH ASS FLOW SLOW PISTIN FLOW SP RIN FLOW SWITGH ASS Y FLOW SWITCH ASSY CLOSEZ r CUTLET PORT FILTER IKLET PORT CHECK VALVE SEAT amp O RING CHECK BALL INFUT SHAFT SEALS amp BUSHING POWER PISTON INPUT SHAFT PRESSURE REGULATOR SPRING ROR JR eco E wi asus es REACTION PISTON REAZTICH PIN THROTTLE VALVE BOWE R PISTON e ES v amp LVvE RETURN SPRING POWER PISTON OUTPUT SHAFT BOWE PLE TON RETURN BALL E BACKUP PUMP Figure 5 2 Hydro Max Booster Components W Series Chassis WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION wj 5 Further movement of the primary piston creates pressure in the primary pressure chamber causing the secondary piston and actuator to move As the secondary piston and actuator move the secondary compensating valve closes shutting off the passage between the secondary pressure chamber and the reservoir section serving the secondary chamber Additional movement of the primary piston causes both chambers to build pressure When the load on the primary piston is removed fluid pressure in each chamber combined with return spring force
24. 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 90 W Series Chassis Brakes 1 The Hydraulic ABS Main Menu will appear Figure 5 45 Fault Screen Use TOOLBOX Software to verify the activation of various system components Valve Activation Menu Activate valves pump and retarder relay Miscellaneous Output Activation Menu Turn ABS indicator lamp on and off Reset components in ECU memory 2 Select the View ECU Faults icon or select Display Faults NOTICE to use the pull down menu This will display the Fault For complete instructions for using this program refer Information screen to the TOOLBOX User s Manual included in this sec tion WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual 91 Brakes Valve Pump and Retarder Relay Activation Retarder Relay Activation on WABCO Antilock Brake System The Valve Activation screen lets you activate the four valves the pump and the retarder relay In addition to NOTICE On some Workhorse vehicles equipped with gaso Checking Tor proper activation this ed provicee an line engines with Hydra matic transmissions and the easy way to make sure the valves are wired properly WABCO Antilock Brake System it has been noted that Component activation status ap
25. FB Park Brake Cable Replacement Lever Type Park Brake Cable Removal 1 Raise the vehicle and support the vehicle with safety stands Refer to Lifting and Jacking the Vehicle in General Information Remove the nut from the equalizer Remove the connector Remove the retainer clip bolts and retainer clips Disconnect the cable from the lever assembly Remove the retaining fingers Remove the cable assembly Attach a piece of wire to the cable to help in the installation NOOO BW PAGE 82 Brakes Park Brake Cable Installation W Series Chassis 1 Install the cable assembly 2 Install the retaining fingers 3 Connect the cable to the lever assembly NOTICE Refer to Fastener Notice in Cautions and Notices 4 Install the retainer clips and the retainer clip bolts 5 Tighten the retainer clip bolts to 17 Nm 13 Ib ft 6 Install the connector 7 Install the nut to the equalizer 8 Adjust the parking brake Refer to Park Brake Cable Service Adjustment 9 Lower the vehicle Park Brake Drum Replacement Park Brake Drum Removal 1 Raise the vehicle and support the vehicle with safety stands Refer to Lifting and Jacking the Vehicle in General Information IMPORTANT Ensure the park brake is released 2 Remove the propeller shaft Refer to Two Piece Propeller Shaft Replacement or Three Piece Propeller Shaft Replacement CAUTION Cap the end of the transmission in order to min
26. Hydraulic ABS from the Main Menu The Hydraulic ABS Main Menu will appear Select the Miscellaneous Output Activation icon or select Component Tests to use the pull down menu to display the Actuate Miscellaneous Output screen This screen provides a check of the ABS indicator lamp In addition it provides a way to check either inlet or outlet activity of the valves pump or retarder relay Component activation status appears in the status box of this screen WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual 5 9 4 Brakes STANDARD SYSTEM TESTING Voltage Check Voltage must be between 9 5 and 14 volts for the 12 volt Test Eaui Dioj ESEEQUIBIDSIES Digital MUEG hydraulic ABS to function properly Check voltage as Use of a DMM with automatic polarity sensing follows is recommended This eliminates the concern 1 Turn ignition ON of the polarity of the meter leads during voltage 2 Check for proper voltage measurements ECU Pins 9 and 3 and 9 and 2 on the black System Requirements and Component Tests connector If voltage is not between 9 5 and 14 volts verify proper Tire Size Range wiring connections Make corrections as required For proper hydraulic ABS operation front and rear tire sizes must be within 1696 of each other Calculate the tire size with the following equation CAUTION When troubleshooting or
27. Pad Replacement Brembo 68mm Caliper Brake Pad Removal CAUTION a During all the operations described below the caliper brake fluid inlet must NOT be dis connected 1 Use a pair of pliers to remove the cotter pins from the pad retainer pins 2 Remove the pad retainer pins 3 Remove the cap from the brake fluid reservoir CAUTION Pushing the caliper pistons back into their bores will cause an increase in the brake fluid level in the reservoir Ensure that the fluid does not overflow as it can damage the painted parts of the vehicle 4 Check the brake fluid level in the reservoir If the fluid level is full use a dedicated siphon tool to remove some of the brake fluid PAGE W Series Chassis 43 5 Slide the caliper outward to apply even pressure on the pistons Use the old inner brake pad or a piece of steel across the pistons to protect them Use a disc brake pad spreader tool to force the pistons back into their bores 6 Remove the brake pads Brakes Clean Dry and Inspect CLEAN 1 Clean the pad attachment plate using a damp cloth 2 Clean the friction surface of the rotor using brake cleaner CAUTION Do not use products that could damage the seals such as paint thinner mineral spirits gasoline etc DRY AND INSPECT 1 Inspect the rotors for wear or damage 2 Check the pistons for wear or damage 3 Check the dust boots for wear or damage 4
28. Repair or replace any worn or damaged parts Brake Pad Installation Brembo 68mm Caliper 1 Install the new pads WARNING The pads must be inserted with the friction material facing the rotor WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual TE 5 2 Install the pad retainer pins It may be necessary to lift PAGE W Series Chassis 44 Brakes 3 Remove inner and outer pads from anchor plate and the pads slightly to align the holes in the pads 3 Use a pair of pliers to install the hitch pins When the hitch pin is installed it should be located between the pad and the caliper housing 4 Pump the brake pedal repeatedly to move the pistons out and press the pads against the rotor Continue pumping the pedal until the usual pedal force and stroke are restored 5 Check the brake fluid level in the reservoir Add fluid if necessary 6 Install the cap on the brake fluid reservoir 7 Burnish the pads Refer to Burnishing the Rotors and Pads When new pads have been installed braking efficiency will be reduced until the brakes have been properly burnished Reduce vehicle speed and avoid sudden or prolonged brak ing until the brakes have been burnished Brake Pad Replacement Bosch ZOH T Caliper Brake Pad Removal Bosch ZOH T Caliper NOTICE Do not allow calipers to hang from the flexible hoses Doing so can damage the hoses
29. and bracket in place on the vehicle 2 Tighten the three mounting nuts to 132 Ib in 15 N m 3 Connect and tighten brake line connections as follows Two small adapters 108 Ib in 12 N m Four large adapters 132 Ib in 15 N m 4 Bleed the brake system per the following instructions 5 Connect the electrical harnesses to the modulator assembly W Series Chassis Brakes ABS BRAKE BLEEDING PROCEDURES General The following brake bleeding methods explain how to bleed the hydraulic ABS modulator assembly during installation or in the event of air in the brake system There are instructions for both pressure and manual bleeding procedures These instructions include the procedure for bleeding both the master cylinder and the brake system In some cases for example if you are replacing only the modulator assembly it may not be necessary to bleed the master cylinder NOTICE The modulator assembly must be handled with appro priate care and should not be exposed to excessive impact or compressed air at the hydraulic ports prior to assembly Failure to bleed the system whenever any hydraulic system fitting is loosened or dis connected will allow air to remain in the sys tem This will prevent the hydraulic pressure in the brake system from rising enough to apply the brakes properly This will cause the stopping distance to increase and can result in serious personal injury Prope
30. bolts and washers to 58 N m 43 Ib ft 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual m 3 Install the parking brake and yoke assembly 4 Tighten the bolt to 110 N m 81 Ib ft 5 Connect the hydraulic line to the parking brake assembly 6 Tighten the hydraulic fitting 7 Install the propeller shaft Refer to Two Piece Propeller Shaft Replacement or Three Piece Propeller Shaft Replacement 8 Lower the vehicle Automatic Apply Park Brake Pump Reservoir Assembly Replacement Automatic Apply Park Brake Pump Reservoir Assy Removal NOTICE When replacing any hydraulic components the hydrau lic system should be flushed with Dexron VI transmis sion fluid SECTION 5 This is to ensure that the hydraulic system is free of contaminants such as metal particles that may have been circulated through the system as a result of a component failure 1 Move the column shift lever to park and apply the manual parking brake 2 Position a drain pan to catch the fluid that leaks out Do not reuse the old fluid 3 Access the panel on the inboard side of the component box 4 Remove the parking brake pump motor assembly electrical connector 5 Remove the pressure indicator switch electrical PAGE 85 W Series Chassis Brakes connector Remove the hydraulic pipes from the solenoid valve 1 Remove the parking brake pump motor a
31. brake caliper Clean Dry and Inspect CLEAN PARTS 1 Thoroughly clean the exterior caliper surfaces using a damp cloth DRY AND INSPECT PARTS 1 Use soft clean paper or cloth rags or compressed air to completely dry parts immediately after cleaning them 2 Carefully inspect each part for wear or damage 3 Repair or replace worn or damaged parts Brake Caliper Installation 1 Position the caliper on the support 2 Install the four caliper to support assembly bolts 3 Tighten the bolts to 435 2 489 6 N m 320 360 Ib ft PAGE W Series Chassis 39 Brakes BRAKE PAD REPLACEMENT Brake Pad Replacement Brembo 52mm Caliper Brake Pad Removal Brembo 52mm Caliper 0 When replacing the brake pads DO NOT disconnect the brake hose fitting from the caliper 1 Check the brake fluid level in the reservoir Figure 5 17 Upper caliper slide bolt removal 2 Remove the protective cap 3 of the upper caliper slide bolt 4 from the caliper slide 5 3 Completely remove the upper caliper slide bolt 4 Take the upper caliper slide bolt 6 out of the caliper slide bracket 7 using a suitable prybar if necessary WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual a 5 40 Brakes 6 Move the caliper body away from the bracket 7 rotating it around the other guide until the pads can be taken out of the caliper s
32. caliper mounting bolt to specified value WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 Toc 5 Install the brake hose retaining clip fastener and torque to vehicle manufacturer s specification 6 If any hydraulic lines were opened or removed bleed brake system IMPORTANT Before moving the vehicle pump the brake pedal sever al times in order to make sure the pedal is firm Do not move the vehicle until you obtain a firm pedal Brake Pad Replacement Meritor Quadraulic Caliper Brake Pad Removal Meritor Quadraulic Caliper 1 Remove the master cylinder reservoir filler cap Check the brake fluid level in the reservoir If necessary remove fluid to keep the reservoir from overflowing when compressing pistons into the caliper 2 Remove the pad retainer spring bolt 3 f Caliper Mounting Bolts Figure 5 24 Caliper Mounting Bolt Location PAGE W Series Chassis 45 3 Compress the caliper pistons 4 Remove the brake pads Brakes Brake Pad Installation Meritor Quadraulic Caliper 1 Inspect the rotor for scoring warping cracks bluing heat spots or other damage or defects and minimum thickness Repair or replace if necessary 2 Inspect the disc brake calipers for leakage damage or defects to piston boots seals or pistons Replace or repair the parts as required 3
33. closes the fluid return port to the pump from As the spool valve moves along its bore the lands the booster pressure chamber and allows hydraulic fluid Prevent fluid flow from the power steering pump to the to enter the booster pressure chamber steering gear This causes the power steering pump to increase fluid pressure to maintain the same flow rate WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS W Series Chassis Service Manual m 5 21 Brakes RETURN TO PUMP RESERVOIR TO POWER m STEERING GEAR spOOL AND SLEEVE POWER STEERING gy wb ASSEMBLY PUMP PRESSURE zx BOOST PRESSURE 77 CHAMBER RATIO LESE Wu dj ET T SPOOL i VALVE OUTPUT ROD BOOST 5 PLISH INPLIT ROD Figure 5 9 Hydro Boost Internal Components If pressure is required for power steering during braking Released Position No Braking the power steering pump increases the pressure The spool valve shifts to an open position and allows more fluid to flow to the power steering gear The system stores enough fluid under pressure for brake application if fluid flow from the power steering pump is not available The brakes can also be applied manually if the reserve system is depleted WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series When the brake pedal is released the spool valve return spring holds the spool valve open In the open position t
34. etc that you observed This will isolate when the DTC failed For an intermittent refer to Testing for Intermittent Conditions and Poor Connections WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual m 5 1 25 DTC P0608 DTC P0608 Step Action Value s No Schematic Reference Instrument Cluster Schematics Connector End View Reference Master Electrical Component List Did you perform the Diagnostic System Check Vehicle Go to Step 2 Go to Diagnostic System Check Vehicle 1 Turn the ignition OFF Go to Diagnostic Aids Go to Step 3 2 Raise the vehicle drive wheels Refer to Lifting and Jacking the Vehicle 3 Start the engine 4 Place the transmission into drive for an automatic transmission or third gear for manual transmission Does the vehicle speedometer indicate a vehicle speed Inspect for poor connections at the harness connector of the PCM Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs Did you find and correct the condition Repair the short to ground in the vehicle speed signal circuit Refer to Wiring Repairs Go to Step 8 Go to Step 7 o mE 2007 WorkhorseCustom Chassis All Rights Reserved W Series Did you complete the repair Test the vehicle speed signal circuit for a short to voltage Refer to Circuit Go to Step 8 Go
35. ground WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 COMPONENT REPLACEMENT J72 PARK BRAKE Park Brake Assembly Replacement CAUTION Block the vehicle wheels to prevent move ment before servicing the park brake assem bly Removal Procedure 1 Raise the vehicle and support the vehicle with safety stands Refer to Lifting and Jacking the Vehicle in General Information IMPORTANT Ensure the park brake is applied 2 Remove the propeller shaft Refer to Two Piece Propeller Shaft Replacement or Three Piece Propeller Shaft Replacement 3 Disconnect the hydraulic line from the brake assembly Install a suitable plug in the hydraulic line and cap the brake assembly fitting to minimize fluid loss 4 Remove the center bolt retaining the yoke to the transmission output shaft Remove the yoke Figure 5 4 Removing the Park Brake Assembly IMPORTANT Cap the end of the transmission in order to minimize fluid loss W Series Chassis 74 5 Inspect the yoke ears for damage and the splines for the following damage Wear Burrs Twisting Brakes The park brake assembly weighs approxi mately 45lbs 20 kg Use a suitable jack to support the brake before removing the attaching bolts Failure to do so may result in personal injury 6 Remove the four bolts attaching the brake assemb
36. has detected a sticky pump relay The pump motor may be permanently running Check the relay and replace if necessary Blink Code 81 SAE Fault Code SID 14 FMI 4 Description ABS Valve Relay Internal Shorted to Ground The ABS ECU has detected a short to ground on the internal valve relay Clear the fault with TOOLBOX software and cycle the ignition If fault repeats replace ABS ECU W Series Chassis Brakes Blink Code 82 SAE Fault Code SID 251 FMI 3 Description Power Supply High Voltage The ABS ECU has detected the supply voltage to be too high for more than 5 seconds Check the alternator and battery Check for faulty valve relay or wiring Blink Code 81 SAE Fault Code SID 251 FMI 4 Description Power Supply Low Voltage The ABS ECU has detected the supply voltage to be too low for more than 5 seconds Check the supply wire battery and fuse Check for faulty valve relay or wiring Blink Code 83 SAE Fault Code SID 254 FMI 12 Description Internal Error The ABS ECU has detected an internal fault Clear the fault with TOOLBOX software and cycle the ignition If fault repeats replace ABS ECU 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 Blink Code 84 SAE Fault Code SID 253 FMI 2 Description EEPROM Checksum Error The ABS ECU has detected a checksum error in the parameters in the EE
37. insta yv d stopping distance to increase and can result retarder it expects to see it every time the vehicle is in serious personal injury powered up Because there are times when an ECU is Correctly discard hydraulic brake fluid that moved to another vehicle or during diagnostic testing is removed from the brake system Hydraulic you may want the ECU to disregard this learned Hy that is 47 i be D nated and can cause damage loss of braking Use the Reset Memorized command for this and serious personal injury l Use only DOT 3 hydraulic brake fluid Do not Wheel Speed use or mix different types of hydraulic brake fluid Th h li ke flui ill Select Wheel Speed to display the Wheel Speed screen 2 Use the Wheel Speed screen to verify that sensors and can cause damage loss of braking and connected at each wheel Speed at a sensed wheel FL serious personal injury FR RL RR indicates sensors are installed but does not verify correct sensor installation CAUTION O E Do not let the brake master cylinder fluid get nd of Line below the minimum level during the bleeding operation Keep the master cylinder reservoir The End of Line Brake Bleed Procedure is accessed filled with new DOT 3 brake fluid Failure to from the HABS main screen Use the Brake Bleed keep the brake reservoir level above mini feature to bleed the expansion chambers mum could result in more air entering sys NOTICE tem
38. making it impossible to effectively bleed the system Before connecting the vehicle to the computer bleed the circuit and master cylinder WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION 8 W Series Chassis Service Manual ca 5 1 1 2 Brakes lil I 5 From the Main Menu select the HABS icon Hydraulic brake fluid is a caustic substance 6 Select End of Line from the HABS Main Menu Contact with hydraulic brake fluid can cause 7 Select Bleed Procedure from the End of Line Menu skin irritation Do not let hydraulic brake fluid touch any painted surfaces as it will remove 8 Choose axle to bleed from the select axle screen the paint Hydraulic brake fluid may also 9 Follow on screen prompts damage certain non metal surfaces Do not Click OK to continue let fluid get on brake pads shoes rotors or disks Click OK to continue 10 Repeat procedure two additional times on this axle el PDI Wie parking prake and DIO ihe Mes Tunn Me This should eliminate all of the air in the chamber ignition off 2 Perform brake bleed procedure for wet module Ti Perton manual Dleed on bleeding the circuit and master cylinder if required 12 Repeat Steps 8 11 for the other axle prior to connecting laptop to truck 13 Test drive the vehicle after bleeding the brakes 3 Connect laptop to the vehicle using the J1587 If a firm brake pedal resistance is fel
39. the specified range the entire time the driveshaft is rotating Go to Step 10 Go to Step 6 WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series Did you find and correct the condition WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual T 5 1 29 Brakes gt l Go to Step 10 Go to Step 8 DTC P0609 Values Replace the EBCM Refer to Control Module References for replacement setup and programming Did you complete the replacement Test the vehicle speed signal circuit for an open a short to ground or a short to voltage Refer to Circuit Testing and Wiring Repairs Did you find and correct the condition Replace the PCM Refer to Control Module References for replacement setup and programming Go to Step 3 System OK Did you complete the replacement 1 Use the scan tool in order to clear the DTCs 2 Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text Inspect for poor connections at the harness connector of the powertrain Go to Step 10 Go to Step 9 control module PCM Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs Did you find and correct the condition Does the reset WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series
40. use of a conventional booster and master cylinder assembly In a remote application the master cylinder reservoir is mounted separately from the master cylinder Basic Operation of Hydro Max Booster Assembly and Master Cylinder Refer to the illustration on the following page to identify the following electrical components of the booster and master cylinder Backup Pump The Hydro Max hydraulic booster has a backup pump which will provide hydraulic boost at a reduced rate if the normal source of fluid is interrupted The signal for operation of the backup pump comes from the flow switch If normal flow is interrupted the flow switch will close and activate the relay which will turn on the backup pump 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION m 9 W Series Chassis 13 Brakes Differential Pressure Switch The differential pressure The 12 volt backup pump can draw a steady state maximum of 55 amps at a power steering fluid temperature of 100 degrees F The Hydro Max Master Cylinder and Booster Components Relay The function of the relay is to provide current to the backup pump when triggered by the flow switch Flow Switch The function of the flow switch is to activate the relay when normal hydraulic power source fluid flow is interrupted turning on the backup pump The flow switch has two terminals A and B Ais
41. 104 System 107 TOOLBOX Start up 108 109 Component 110 WABCO FAULT CODES 113 DIAGNOSTIC TROUBLE CODES 124 DITC FOGOS TT 124 DIC 20 2 E snm 127 2007 WorkhorseCustom Chassis All Rights Reserved W Series Chassis W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual T 5 5 Brakes THIS PAGE LEFT BLANK INTENTIONALLY WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS W Series Chassis SECTION MMC rvice Manual Manua 9 UU Brakes FASTEN ER TIGHTEN IN G Caliper to caliper EN bracket bolts SPECIFICATIONS Brembo 68mm Caliper Caliper to caliper mounting bracket bolts 93 107 126 145 Bosch ZOH T Caliper Ib ft N m ABS sensor bolt Bosch ZOH T Caliper 12 16 Ib ft 17 21 N m Caner mrdr momia bole ABS sensor bolt Meritor Quadraulic M Q E lic Cali 225lbft 305 Nim Caliper 124 Ib in 14 Meritor Quadraulic Caliper Caliper mo
42. 8mm Caliper IN Brake Pad minimum thickness above metal discard Bosch ZOH T Caliper A Brake Pad minimum thickness above metal discard Meritor Quadraulic 25 3 175mm Caliper Brake fluid DOT Rotor diameter Brembo 52mm Caliper 12 25 in 307mm Rotor diameter Brembo 68mm Caliper 12 88 in 322mm Rotor diameter Bosch ZOH T Caliper 14 28 in 357mm Rotor diameter Meritor Quadraulic 15 38 in 390 7mm Caliper Refer to Marking on Rotor Rotor thickness discard Brembo 68mm Caliper Refer to Marking on Rotor Rotor thickness discard Bosch ZOH T Caliper Refer to Marking on Rotor Rotor thickness discard Meritor Quadraulic Caliper Refer to Marking on Rotor AMMCO Data Rough Cut Finish Cut Spindle Speed 150 RPM 150 RPM Depth of Cut 0 127 mm 0 051 mm per side 0 005 in 0 002 in Total Cross Feed 0 152 0 254 mm 0 051 mm max per revolution 0 006 0 01 in 0 002 in Vibration Yes Vas Dampener irl Patt Swirl Pattern ves 120 Grit BRAKE LATHE SPECIFICATIONS ACCU TURN Data Cut Information Spindle Speed 150 RPM Tool Cross Feed per revolution 0 076 mm 0 003 in Tool Bit Nose Radius 0 396 mm 0 003 in Vibration Dampener Swirl Pattern 120 Grit Yes Yes WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSI
43. CM detects that the commanded state of the driver and the actual state of the control circuit do not match The condition must be present for a min of 5 seconds Action Taken When the DTC Sets The PCM stores the DTC information in memory PCM records the operating conditions at the time the DTC sets The PCM displays the failure information in the Failure Records on the scan tool W Series Chassis IPU Brakes Conditions for Clearing the DTC e The history DTC clears after 40 malfunction free warm up cycles e The DTC becomes history when the conditions for setting the DTC are no longer present e The PCM receives the clear code command from the scan tool Diagnostic Aids IMPORTANT Remove any debris from the PCM connector surfaces before servicing the PCM Inspect the PCM connector gaskets when diagnosing replacing the PCM Ensure that the gaskets are installed correctly The gaskets pre vent water intrusion into the PCM Using Freeze Frame and or Failure Records data may aid in locating an intermittent condition If you cannot duplicate the DTC the information included in the Freeze Frame and or Failure Records data can aid in determining how many miles since the DTC set The Fail Counter and Pass Counter can also aid determining how many ignition cycles the diagnostic reported a pass and or a fail Operate the vehicle within the same freeze frame conditions RPM load vehicle speed temperature
44. Clean and inspect the lining rail covers If they are worn they must be replaced NOTICE The inboard and outboard brake pads are identical except when they are equipped with a mechanical wear sensor 4 Install the brake pads Ensure that the friction surface is against the rotor Install the pad retainer spring and tighten the bolt to 30 Ib ft 40 N m of torque NOTICE Brake pad clearance adjustment is automatic 5 Fill the master cylinder reservoir with new clean high performance DOT 3 brake fluid Make several brake applications to move the brake pistons and linings out into contact with the brake rotors 6 Recheck master cylinder reservoir and top off as necessary to manufacturer s recommended level 7 Bleed the brake system Refer to Brake System Bleeding 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 5 Bleed Screw Replacement Bleed Screw Removal 1 Remove the cap from the bleed screw 2 Loosen the bleed screw 3 Inside the vehicle position a spacer between the front edge of the driver seat and brake pedal so that the pedal is pressed throughout the repair This is done to avoid any leakage of brake fluid from the brake hose 4 Remove the bleed screw Inspect 1 Carefully inspect threads in the caliper bleed port for damage 2 Repair or replace worn or damaged parts Bleed Screw Installation 1 Th
45. Inlet Valve Shorted to Ground The ABS ECU has detected that the inlet solenoid valve X1 4 is shorted to ground Check the cables from the ECU to the valve for damage Blink Code 21 SAE Fault Code SID 49 FMI 3 Description Right Front Outlet Valve Shorted to Battery Voltage The ABS ECU has detected that the outlet solenoid valve X1 9 is shorted to battery voltage Check the cables from the ECU to the valve for damage Blink Code 21 SAE Fault Code SID 49 FMI 5 Description Right Front Outlet Valve Open The ABS unit has detected an open circuit between the pins that connect to the left front ABS outlet valve on the X1 connector pins 9 amp 2 The open circuit may be caused by a bad solenoid valve or an open in the cable sockets Use an ohmmeter to check the resistance and determine the bad component 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 9 Blink Code 21 SAE Fault Code SID 49 FMI 6 Description Right Front Outlet Valve Shorted to Ground The ABS ECU has detected that the outlet solenoid valve X1 9 is shorted to ground Check the cables from the ECU to the valve for damage Blink Code 22 SAE Fault Code SID 14 FMI 3 Description ABS Valve Relay Internal Shorted to 12V The ABS ECU has detected a short to 12V on the internal valve relay Clear the fault with TOOLBOX software and cycle the ignition If fault repe
46. Modulator nes aed iere acad 87 Wheel Speed Sensors 88 Sensor Spring IB Coconut 88 Tooth Wheel d boves dud Cacao nii aua tau aa vies 88 ABS Indicator Lampes dada 89 ABS Diagnostic PrOGBQUE BS 89 Systemi Diagnostics la Strain 89 Valve Pump and Retarder Relay Activation 91 Retarder Relay Activation on WABCO Antilock Brake o o o o 91 Reset Memorized TTC 92 Fault Information 2 93 ABS Indicator Lamp 93 Standard System 94 System Requirements and Component Tests 94 Standard Component Testing 96 Component Removal and Installation 100 SENSONE ics en eo ey ne ee eee 100 Wheel Speed Sensor Replacement Front Axle 100 Wheel Speed Sensor Replacement Rear Axle 101 Modulator Assembly ene ean renti 102 ABS Brake Bleeding Procedures 103 SSBC Me M Y 103 Brakes Pressure Fill and
47. N m 9 W Series Chassis 60 Clean Dry and Inspect Brembo 52mm Caliper Brakes CLEAN 1 Clean the caliper guide pin bore 2 Clean the dust boot DRY AND INSPECT 1 Use soft clean paper or cloth rags or compressed air to completely dry parts immediately after cleaning them 2 Inspect the dust boots for tears or other damage 3 Inspect the guide pin bores for wear or damage 4 Repair or replace worn or damaged parts Guide Pin and Boot Installation Brembo 52mm Caliper 1 Lubricate the following components with brake grease a Inside of the caliper guide pin bores in the calipers b The outside of the caliper guide pins c The inside of the dust boots 2 Install the dust boots on their seats 3 Install the guide sleeves 4 Install the caliper Refer to Caliper Replacement Brembo 52mm Caliper Caliper Guide Pin and Dust Boot Replacement 68mm Caliper Guide Pin and Dust Boot Removal Brembo 68mm Caliper 1 Remove the caliper Refer to Caliper Replacement Brembo 68mm Caliper WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 2 Remove the guide sleeves from the caliper 3 Remove the dust boots from the caliper Clean Dry and Inspect Brembo 68mm Caliper CLEAN 1 Clean all the surfaces of the caliper body 2 Clean the dust boots 3 Clean the guide pin bores DRY AND INSPECT
48. PROM Clear the fault with TOOLBOX software and cycle the ignition If fault repeats replace ABS ECU Blink Code N A SAE Fault Code SID 55 FMI 2 Description Brake Light Switch Failure The ECU has detected a failure in the brake light switch The brake light switch data is erratic Check for short to 12V or short to ground PAGE W Series Chassis 1 23 Brakes Blink Code N A SAE Fault Code SID unk FMI unk Description Unknown SID FMI The ABS ECU has reported a System ID and Failure Mode Identifier that is not recognized by this document Please contact Workhorse Technical Assistance Center at 877 246 7731 WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 5 DIAGNOSTIC TROUBLE CODES DTC P0608 Circuit Description The PCM creates the vehicle speed output signal by pulsing the circuit to ground The PCM pulses the circuit at the same rate as the vehicle speed signal input The PCM monitors the voltage on the vehicle speed output circuit If the PCM determines the voltage is out of the normal operating range a DTC sets DTC Descriptor This diagnostic procedure supports the following DTC DTC P0608 Vehicle Speed Output Circuit Conditions for Running the DTC The engine speed is greater than 400 RPM The ignition voltage is greater than 6 volts but less than 18 volts Conditions for Setting the DTC P
49. S Service Manual INTRODUCTION SECTION 5 TOC OBJECTIVES OF THIS SECTION This section is intended to provide information regarding the hydraulic brake system components This is specific to the W Series Workhorse Chassis Explanations for most components will include purpose function operation and location Guidance for proper and safe disassembly inspection repair and assembly are provided DESCRIPTION AND OPERATION There are three brake systems on a Workhorse motor home chassis e Service Brake System Antilock Brake System ABS e Park Brake System W Series Chassis 8 Brakes SERVICE BRAKE SYSTEM DESCRIPTION The service brakes are the primary brake system for the chassis The system uses hydraulic pressure from a foot pedal operated master cylinder to actuate cylinders that apply the brake pads to the braking surfaces on the brake rotors The amount of hydraulic pressure in the system applied by the driver determines how much pressure is applied to the brake pads on the brake rotors Hydraulic pressure created by the master cylinder operation is transmitted through brake lines and hoses to the wheel cylinders and calipers The hydraulic pressure forces the pistons in the wheel cylinders and or calipers outward causing the brakes to be applied Braking action occurs as a result of friction between the brake lining and the metal surface of the rotor disc Brake power is generated when th
50. S ECU has detected that the outlet solenoid valve X1 8 is shorted to ground Check the cables from the ECU to the valve for damage Blink Code 27 SAE Fault Code SID 251 FMI 5 Description Power Supply Ground Reference Missing The ABS ECU has detected the supply voltage ground reference wire is broken or shorted to plus voltage Check the wiring W Series Chassis 117 Brakes Blink Code 31 SAE Fault Code SID 2 FMI 1 Description Right Front Wheel Sensor Air Gap Too Large The ABS ECU has detected that the output voltage signal of the wheel sensor is too low Check for loose wheel bearings or excessive hub run out Push the wheel sensor all the way in until it contacts the tooth wheel Do not pry or push sensors with sharp objects Sensors will self adjust during wheel rotation To check the amplitude with a voltmeter disconnect the X3 connector from the ECU and measure across pins 4 and 9 Blink Code 32 SAE Fault Code SID 1 FMI 1 Description Left Front Wheel Sensor Air Gap Too Large The ABS ECU has detected that the output voltage signal of the wheel sensor is too low Check for loose wheel bearings or excessive hub run out Push the wheel sensor all the way in until it contacts the tooth wheel Do not pry or push sensors with sharp objects Sensors will self adjust during wheel rotation To check the amplitude with a voltmeter disconnect the connector X3 from the ECU and measure across pins 5 and 8
51. T Caliper earth itunes 50 System Adjustment Procedures Manual Apply Seal and Dust Boot Replacement acide cim vate 76 Meritor Quadraulic Caliper 51 Park Brake Cable Adjustment eee 76 Caliper Piston Replacement Brembo 52mm Caliper 52 Park Brake Service Manual Apply Park Brake Caliper Piston Replacement Brembo 68mm Caliper 55 Park Brake Shoe Replacement 77 Caliper Piston Replacement Bosch ZOH T Caliper 57 Park Brake Pedal Replacement 78 Park Brake Lever Replacement 79 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual Park Brake Pull Switch Replacement Park Brake Cable Replacement Pedal Type Park Brake Cable Replacement Lever Type 82 Park Brake Drum Replacement 82 Park Brake Drum Backing Plate Replacement 84 Automatic Apply Park Brake Assembly Replacement 84 Automatic Apply Park Brake Pump Reservoir Assembly Replacement 85 ANTILOCK BRAKE SYSTEM ABS 86 Antilock Brake System ABS Components 87 ABS Electronic Control Unit 87
52. UMA EEL ra AAi rE LEYT IM Iza SFY LPT i Diki 5 r znHoAnm PTIT amp YEN ic eee TTE DES 105 1 zepa S RAE St RE DUANE t SATY 0 rust PRAS OLILLI PI mper uny Ba vay 1 j sem MT RELA 1755 4 F Wa m 1 a Usk ERI SE wpa 405764 E ALD JA SZ ILIO nll ES NIS TEEL PLUG tit Pol GPT LOKAL Figure 5 3 Hydro Max Master Cylinder Components WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS 45 W Series Chassis Service Manual Em Brakes FLUID LEVEL INDICATOR SWITCH FLOW SWITCH HARNESS SROUND E TE 3 FLOW SWITCH LoIFFEREN IAL PRESSURE SWI TCH BACKUP PUMF 4 6 CHASSIS GROUND Figure 5 4 Hydro Max Electrical Components WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 HYDRAULIC FLUIDS The Hydro Max booster uses power steering fluid as the medium of transmitting power The master cylinder uses DOT 3 brake fluid per SAE J1703 unless otherwise specified on the top of the reservoir Service maintenance of motor vehicle brake fluid in motor vehicle brake actuating systems is covered in SAE J1707 informatio
53. USTOM CHASSIS SECTION 8 W Series Chassis Service Manual ca 5 36 Brakes CAUTION SEEESFRECEEFEFEEFEOIENPECE If leaks are found correct the leak before returning the vehicle to service 9 If rotors were cleaned or if a new rotor was installed burnish the pads Refer to Burnishing the Rotor and Pads N BRAKE CALIPER REPLACEMENT BOSCH ZOH T CALIPER Brake Caliper Removal 1 Remove two thirds of the brake fluid from the master cylinder 2 Raise the vehicle Refer to Lifting and Jacking the Figure 5 12 C Clamp Usage Vehicle in General Information 3 Support the vehicle with safety stands 8 Remove the C clamp 9 Disconnect brake fluid line from caliper and cap line k Mark the relationship OFEN whee ta Nub to prevent brake fluid leakage or contamination in the 5 Remove the tire and wheel assembly Refer to Tire brake line ang MIR yal 10 Remove upper top caliper mounting bolt securing the 6 Position a C clamp and tighten until the piston bottoms caliper to the upper guide pin lee bore 11 Remove lower bottom caliper mounting bolt securing 7 Remove the brake hose retaining fastener the caliper to the lower guide pin 12 Move caliper assembly away from rotor WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual 5 37 Brakes Figure 5 14 Lubricate caliper s
54. WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 9 Submerge the tubing a container of clean hydraulic brake fluid 10 Loosen the bleeder fitting until the fluid begins to flow about 3 4 turn Let the hydraulic fluid flow out of the fitting until it is free of air bubbles 11 Tighten firmly to secure the fitting 12 Repeat Steps 5 through 8 to bleed the remaining three brake actuators Bleed in sequence of the longest to shortest circuit from the modulator assembly 13 Turn off bleed equipment and remove pressure Remove bleed device and check fluid level in reservoir Fill if required Replace reservoir cap and dispose of used brake fluid 14 Remove wheel chocks Manual Bleed Procedure 1 Apply the parking brake and chock the tires Turn the ignition OFF and disconnect the battery terminals NOTICE The ignition must remain off for the entire bleed pro cedure energizing the unit during bleeding must be impossible 2 Fill the reservoir with DOT 3 hydraulic brake fluid 3 Depress the brake pedal five times using the stroke between 1 3 travel and maximum travel in 5 seconds 4 Release the pedal for 5 to 10 seconds Air bubbles will rise into the reservoir while depressing and releasing pedal 5 Repeat Steps 3 and 4 another three times or until sufficient pedal resistance is felt W Series Chassis
55. ake rotor using brake cleaner W Series Chassis 64 Non directional Refinishing Brakes It is very important that you make the brake rotor surface non directional Dress the brake surfaces with a sanding disc tool such as the Ammco 8750 Safe Swirl Disc Rotor Grinder Accu turn 4331 79 Non directional Swirl Finisher or the equivalent Use 120 grit aluminum oxide sandpaper STANDARD METHOD IMPORTANT The finished brake rotor surface should be as close to that of a new brake rotor as possible Failure to obtain the best possible brake rotor finish can affect braking performance Sand each brake rotor surface using moderate pressure for a minimum of 60 seconds ALTERNATE METHOD If the brake lathe is not equipped with an adequate non directional finishing tool use a sanding block with 150 grit aluminum oxide sandpaper 1 Run the brake rotor at the equipment manufacturer s highest recommended cutting speed IMPORTANT The finished brake rotor surface should be as close to that of a new brake rotor as possible Failure to obtain the best possible brake rotor finish can affect braking performance 2 Sand each brake rotor surface using moderate pressure for a minimum of 60 seconds 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 5 For maximum braking efficiency the rotors must be prepared for operation This preparation i
56. al W Series Chassis 24 When the vehicle is loaded unequally the most heavily loaded wheels require more braking power than the other wheels Loose front wheel bearings may cause the following Brake rotor tilt Spotty contact with the brake linings Erratic braking action Brakes The brakes will pull the vehicle to one side if the front suspension is not aligned correctly This will be very noticeable if the caster and the camber are not within specifications EXTERNAL CONDITIONS THAT AFFECT BRAKE PERFORMANCE Tires Tires with unequal contact and grip on the road cause unequal braking Make sure the inflation and tread pattern of the right and left tires is about equal Vehicle Loading When the vehicle has unequal loading the most heavily loaded wheels require more braking force than the others Front Wheel Bearings Loose front wheel bearings permit the rotor to tilt and to have poor contact with the linings This may cause erratic braking 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 5 Misalignment of the front end particularly camber and caster causes the brakes to pull to one side BRAKE FLUID LEAKS Toc Front End Alignment Use the following procedure in order to test for brake problems that may be caused by fluid leaks 1 Start the engine and run the engine at idle speed 2 Shift the transmissi
57. al Multimeter DMM probe can damage the connector terminal and cause a poor connection A damaged terminal condition is very hard to diagnose IMPORTANT The amount of time it takes for the parking brake to release will vary based on the temperature and battery voltage In extreme cold weather it can take up to 15 seconds to release the parking brake This is normal system operation Before beginning diagnosis on the automatic apply park brake system you need a detailed description of when the condition occurred from the owner This information can be useful in duplicating the condition Always begin diagnosis with a visual inspection of all connectors wiring wire routing and retention and system components Many times a disconnected or loose connector blown fuse open circuit breaker corroded terminal or miss routed wire is the cause of a malfunction W Series Chassis 76 Brakes SYSTEM ADJUSTMENT PROCEDURES MANUAL APPLY PARK BRAKE Park Brake Cable Adjustment Manual Park Brake Adjustment ADJUSTMENT WITH DRUM OFF PRIMARY PROCEDURE 1 Use a 12 inch caliper or inside micrometer to measure the inside diameter of the drum Subtract 0 025 inches from the drum inside diameter measurement Set the measurement caliper to this value and lock the setscrew 2 Rotate the axle input flanged yoke so the yoke is in the vertical position to provide clearance for the caliper 3 Place the pre adjusted caliper ov
58. al T 99 Brakes Normally there should be between 6 0 to 7 0 ohms an open in the cabling somewhere Refer to the vehicle measured between the pin of the valve and ground wiring diagram for connectors and pin outs and then A resistance measurement should be taken with an check for continuity from valve to ECU ohmmeter Make sure that the ignition is turned off You If the reading is between 6 0 and 7 0 ohms the valve and may start with either Step Aor Step B whichever is cabling is good Reconnect the ABS ECU and turn on easiest to access the ignition Use TOOLBOX to check if the fault is still active If it is still active replace the ABS ECU STEPA f Outlet Valve Open Check To measure the resistance at the ABS Modulator Unit connector disconnect the valve cable from the unit Normally there should be between 3 0 to 4 0 ohms Connect the ohmmeter across each valve solenoid coil measured between the pin of the valve and ground to ground A resistance measurement should be taken with an If the reading is not between 6 0 and 7 0 ohms clean ohmmeter Make sure that the ignition is turned off You the electrical contacts on the connector and check the may start with either Step Aor Step B whichever is resistance again If still out of range replace the ABS easiest to access valve Turn the ignition back on and use TOOLBOX to verify that the fault is not active STERA e If the reading is between 6 0 7 0 ohms the valve To measu
59. always wear If the reading is not between 3 0 and 4 0 ohms there is safe eye protection when you perform vehicle an open in the cabling somewhere Refer to the vehicle maintenance or service wiring diagram for connectors and pin outs and then check for continuity from valve to ECU r uni from moving Support the vehicle with safety e If the reading is between 3 0 4 0 ohms the valve and stands Do not work under a vehicle sup cabling is good Reconnect the ABS ECU and turn on ported only by jacks Jacks can slip and fall the ignition Use TOOLBOX to check if the fault is still over Serious personal injury can result active If it is still active replace the ABS ECU To avoid damage to the electrical system or ABS components when welding on an ABS COMPONENT REMOVAL AND INSTALLATION equipped vehicle disconnect the power con nector from the ECU Apply the parking brakes Chock the rear tires to prevent vehicle movement If necessary raise the front Sensor Lube Specification tires off the ground Put safety stands under the axle Disconnect the fasteners that hold the sensor cable to other components Disconnect the sensor cable from the chassis harness Sensors N Meritor WABCO specifications call for a sensor lubricant with the following characteristics Lube must mineral oil based and contain 4 Remove the sensor from the sensor holder Twist and molydis
60. and Buzzer Do Not Shut Off Booster Backup Pump Runs Continuously The booster backup pump can run only if the relay is closed The relay will be closed only if 1 The flow switch is closed and there is power to the coil 2 The relay is stuck closed Booster Backup Pump Does Not Run The booster backup pump will not run if there is no voltage to the motor or if the motor is damaged e g burned out or jammed A no voltage condition can occur because 1 Battery is dead 2 Relay is stuck 3 Wires are broken battery to motor circuit or ignition switch brake light switch to booster flow switch circuit 4 Booster flow switch is not closed to ground W Series Chassis 31 Brake Pedal Feels Spongy Soft or Springy Brakes If the brake pedal does NOT fall with steady foot pressure but feels spongy soft or springy the problem is probably caused by air trapped in the brake fluid system Start by bleeding the brake system at the caliper furthest from the master cylinder and work from the back to the front of the vehicle Brake Pedal Feels Very Hard The most common reasons for a very hard brake pedal are 1 Insufficient flow or pressure from the power steering pump 2 The ABS hydraulic unit is blocking the flow of brake fluid to the calipers Potential Master Cylinder and Booster Leak Points Most external leakage is easy to detect by wetness and or appearance of fluid drops However slight dampness no dro
61. ard direction brake pedal for at least 30 seconds WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 43 Push the brake pedal repeatedly to move the pistons against the disc until the pedal force and usual stroke are restored 44 Check the brake fluid level in the reservoir and top off if necessary CAUTION If there are fluid leaks from the caliper repeat all the above operations to ascertain the cause and correct the fault Clean Dry and Inspect Brembo 52mm Caliper CLEAN PARTS For ground or polished parts CAUTION Do not use hot solution tanks or water and alkaline solutions to clean ground or pol ished parts Damage to parts will result Use safety solvent or equivalent to clean the surfaces of ground or polished parts For rough metal parts Use a cleaning solvent or weak alkaline solution in a hot solution tank to clean rough metal parts If a hot solution tank is used follow the instructions below 2 Place the rough parts in the hot solution tank 3 Leave the rough parts in the tank until they are completely cleaned and heated 4 Remove the rough parts from the tank W Series Chassis 49 5 Thoroughly wash the rough parts with water until the alkaline solution is completely washed off of the parts Brakes DRY AND INSPECT PARTS 1 Use soft clean paper or cloth rags or compres
62. ats replace ABS ECU Blink Code 22 SAE Fault Code SID 42 FMI 3 Description Left Front Inlet Valve Shorted to Battery Voltage The ABS ECU has detected that the inlet solenoid valve X1 3 is shorted to battery voltage Check the cables from the ECU to the valve for damage W Series Chassis 114 Brakes Blink Code 22 SAE Fault Code SID 42 FMI 5 Description Left Front Inlet Valve Open The ABS unit has detected an open circuit between the pins that connect to the left front ABS inlet valve on the X1 connector pins 2 amp 3 The open circuit may be caused by a bad solenoid valve or an open in the cable sockets Use an ohmmeter to check the resistance and determine the bad component Blink Code 22 SAE Fault Code SID 42 FMI 6 Description Left Front Inlet Valve Shorted to Ground The ABS ECU has detected that the inlet solenoid valve X1 3 is shorted to ground Check the cables from the ECU to the valve for damage Blink Code 22 SAE Fault Code SID 48 FMI 3 Description Left Front Outlet Valve Shorted to Battery Voltage The ABS ECU has detected that the outlet solenoid valve X1 10 is shorted to battery voltage Check the cables from the ECU to the valve for damage 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 5 Toc Blink Code 22 SAE Fault Code SID 48 FMI 5 Description Left Front Outlet Valve Open
63. causes the primary and secondary pistons to return to their initial released positions Each actuator opens its respective compensating valve reopening the passage between the individual reservoir sections and its associated pressure chamber Should the rate of release be great enough to cause a partial vacuum in the chamber the compensating valve will open to allow replenishment of fluid into the cylinder bore Any excess fluid remaining at the end of the stroke due to pumping and or volume change due to temperature fluctuation is released to the reservoir as the compensating valves open The primary circuit is separated from the secondary hydraulic circuit Hydraulic leakage in one circuit does not affect the function of the other circuit W Series Chassis 12 A fluid level indicator switch is available It illuminates a light on the dash panel to warn of low brake fluid level in the master cylinder reservoir A low fluid level can result from brake shoe lining wear or it can occur if there is an external leak in the vehicle brake system Brakes A differential pressure switch is available It illuminates a light on the dash panel to warn when there is a pressure differential between the primary and secondary brake circuits caused by a leak in one circuit This may occur when one circuit leaks or is improperly bled A remote reservoir application is available where under the hood space constraints prohibit the
64. ctedly J72 Park Brake Description MOTOR ELECTRICAL CONNECTOR The J72 option code park brake system is made W Series Chassis PUMP amp MOTOR COMTROL MODULE up of two major separate components or systems Figure 5 28 J72 Actuator Assembly the actuator and the brake assembly Each of the components is serviced as an assembly WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION Figure 5 29 J72 Brake Assembly System Overview The J72 system incorporates a unique full circle parking brake The automatic electric hydraulic parking system controls the transmission propeller shaft mounted parking brake This system consists of a pump motor relay vehicle ignition relay electric hydraulic pump reservoir proportional relief solenoid valve pressure transducer and an electronic control module ECM The ECM monitors seven inputs from the vehicle and controls the pump motor relay auto park light park brake warning light buzzer proportional valve and pressure transducer W Series Chassis 67 The park brake is released by pushing the park brake switch pull button in and moving the shift lever on the steering column from the park position or select D or on the push button shift control NOTICE Both situations must occur for the brake to release Brakes Once the ECM receives t
65. d out of the caliper CAUTION While pressing the pistons back into their bores be careful to not damage the insulat ing ring and the dust covers The dust covers must not be twisted or allowed to trap air If air becomes trapped in the dust cover use a flat blade to gently lift the edge of the seal to release the air CAUTION Do not place your fingers in front of the pis ton in an attempt to catch or protect it when applying compressed air This could result in serious injury WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 CAUTION prevent serious personal injury always wear safe eye protection when you perform vehicle maintenance or service 5 Tighten the bleed screw to 14 N m 124 Ib in 6 Install a block of wood into the caliper in front of the caliper pistons CAUTION Sas When removing the pistons from the caliper bore only direct enough compressed air into the caliper brake fluid inlet to ease the pistons out of the bore Do not exceed 25 psi 172 kPa Damage to components will result 7 Apply low air pressure no more than 25 psi 172 kPa to the fluid port in the caliper to move the caliper pistons out to the wood block 8 Remove the pistons 9 Remove the dust boots and the piston seals Refer to Seal and Dust Boot Replacement Brembo 52mm Caliper Clean Dry and Inspect Br
66. d vibration during brake applications Refinish or replace a brake rotor that does not meet these specifications Brakes Brake Rotor Lateral Runout Check The best way to check lateral runout is with the wheels still installed on the vehicle This gives a much more accurate reading of the Total Indicated Runout TIR under real braking conditions If equipment is not available to perform the check with the wheels installed the next best reading can be made with the wheels removed but with the brake caliper still installed In some cases excessive lateral runout can be improved by indexing the brake rotor on the hub that is one or two bolt positions from the original position If the lateral runout cannot be corrected by indexing the brake rotor check the hub and bearing assembly for excessive lateral runout or looseness If the hub and bearing assembly lateral runout exceeds 0 040 mm 0 0016 in replace the hub and or bearing assembly if necessary If the lateral runout is not within specifications refinish or replace the brake rotor as necessary 1 Set the parking brake 2 Block the vehicle wheels 3 Raise the vehicle 4 Support the vehicle with safety stands 5 Remove the tires and wheels 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual TOC SECTION 6 Clean the brake rotor surface 7 f the vehicle is equipped with standard wheel bearings n
67. dges of rotor and on caliper housing Suggested Correction Clean or replace as necessary Condition Glazed pads Suggested Correction Resurface or replace pads in axle sets only Worn pad or pad installed backward Replace pads in axle sets only with friction surface against the rotor Weak pad retainer spring Install new pad retainer spring Pad wear indicator contacting Install new pads in axle sets only rotor Faulty caliper alignment permitting rotor to scrape on housing Correct the alignment Foreign material embedded in Replace pads in axle sets only linings Brake Noise Diagnosis Groan Condition Pressure on the brake pedal too light Suggested Correction Slightly increase the pedal effort to eliminate noise Brake Noise Diagnosis Rattle Condition Excessive clearance between the shoe and caliper Suggested Correction Install new pads Pad retainer spring missing or not properly positioned Install new pad retainer spring or position correctly BRAKE ROTORS HUB AND ROTOR ASSEMBLIES The hub and rotor assemblies consist of a hub and rotor fitted with bearing cups and wheel attachment studs For ABS operation speed sensor reluctor rings are used There are different types of ABS reluctor rings that may be used Cast in ABS reluctor ring typically 100 slots A separate ABS reluctor ring m
68. e 86 Brakes ANTILOCK BRAKE SYSTEM ABS The W16 W18 W24 W25 W42 Series chassis utilize the Meritor WABCO Hydraulic Anti lock Braking System ABS This system is an electronic wheel speed monitoring and control system NOTICE Refer to prior model year service publications for diag nostic information for the Kelsey Hayes ABS used on the W20 W22 Series chassis W Series Chassis ABS wheel sensors detect wheel speeds The sensors generate signals that are transmitted to an Electronic Control Unit ECU If the wheels start to lock the ECU signals the modulator assembly to regulate the brake pressure of each locking wheel During an ABS stop a solenoid valve in the modulator assembly is rapidly pulsed that is it opens and closes several times per second to control the brake pressure When this occurs drivers may notice a pulsation of the brake pedal An ABS indicator lamp on the vehicle dash alerts the driver to a possible system fault and provides blink code information to diagnose the system If the ABS indicator lamp comes on during normal vehicle operation drivers may complete their trip but are instructed to have their vehicles serviced as soon as possible 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual E 5 Brakes In the unlikely event of an ABS system malfunction the ABS in t
69. e completely cleaned and heated 3 Remove the rough parts from the tank 4 Thoroughly wash the rough parts with water until the alkaline solution is completely washed off of the parts DRY AND INSPECT PARTS 1 Use soft clean paper or cloth rags or compressed air to completely dry parts immediately after cleaning them 2 Carefully inspect each part for wear or damage 3 Repair or replace worn or damaged parts Seal and Dust Boot Installation Meritor Quadraulic Caliper 1 Lubricate the new seals with brake grease 2 Install the new seals in the seats inside the caliper body Make sure the seals are properly seated before continuing 3 Lubricate the pistons around their outer diameter with brake grease 4 Install dust boot on the caliper 5 Install the pistons Refer to Caliper Piston Replacement Meritor Quadraulic Caliper W Series Chassis Brakes 6 Install the caliper Refer to Caliper Replacement Meritor Quadraulic Caliper Caliper Piston Replacement Brembo 52mm Caliper Caliper Piston Removal Brembo 52mm Caliper Remove the caliper Refer to Caliper Replacement Brembo 52mm Caliper Loosen the bleed screw but do not remove it Place one end of a hose on the tip of the bleed screw and the other end in a container to catch the brake fluid as it drains Use disc brake pad spreader tool to press both pistons back into their bores which will force the brake flui
70. e ABS ECU has detected a failure in the hydraulic pump motor Check the hydraulic pump and the pump wiring W Series Chassis 121 Brakes Blink Code 77 SAE Fault Code SID 54 FMI 3 Description Hydraulic Pump Motor Failure 1 The ABS ECU has detected a failure in the hydraulic pump motor A high level at the motor monitor pin X2 10 has been detected without the pump motor being activated Check the hydraulic pump and the pump wiring Blink Code 78 SAE Fault Code SID 30 FMI 3 Description Pump Motor Relay Shorted to 12V The ABS ECU has detected a short to battery voltage on the Pump Motor relay output X2 6 Check the wiring X2 6 should go to one end of the Pump Motor relay only Blink Code 78 SAE Fault Code SID 30 FMI 5 Description Pump Motor Relay Open Circuit The ABS ECU has detected an open circuit on the Pump Motor relay output X2 6 Check the wiring X2 6 should go to one end of the retarder relay WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 9 Blink Code 78 SAE Fault Code SID 30 FMI 6 Description Pump Motor Relay Shorted to Ground The ABS ECU has detected a short to ground on the Pump Motor relay output X2 6 Check the wiring X2 6 should go to one end of the Pump Motor relay only Blink Code 78 SAE Fault Code SID 30 FMI 7 Description Pump Motor Relay Sticky Pump Relay The ABS ECU
71. e Auto Park IGN relay by Power should be present when the brake is applied substituting a known good relay of the same type and the ignition is in the ON position 5 Check the function of the Park Brake Pull Button relay Pind 2 cavity 4 2 by substituting a known good relay of the same type Ground should be present when the brake is applied 6 Check for leaks in the hydraulic lines Correct any leaks Pin 5 Backprobe Cavity 5 with the brake applied Ground should be present found 7 Check for power to the motor If power is not present Pin 6 through Pin 8 Not used check for continuity on the power feed circuit If power Pin 9 Backprobe Cavity 9 with the brake applied is present check for continuity on the ground circuit Ground should be present 8 Check for motor function by providing battery voltage to Pin 10 Check for battery voltage on ECM Pin 10 If no pin A of the motor connector and ground to pin B of the voltage is present check the fuse and the circuit motor connector If the motor does not function replace Pin 11 Pin 11 provides the speed signal from the ABS it module Pin 12 Check for battery voltage on ECM Pin 10 with the vehicle in PARK If no voltage is present check the fuse and the circuit to the PNP switch Pin 13 Backprobe Cavity 9 with the brake applied Ground should be present Pin 14 Pin 14 supplies the ECM with chassis ground Backprobe Cavity 14 and check for
72. e MAIN MENU Most TOOLBOX features are accessible through pull down menus Many of these features may also be accessed by a shortcut icon TOOLBOX Start up At the Main Menu you may select a shortcut icon to Exit TOOLBOX Go to Tractor ABS diagnostics Go to Trailer ABS diagnostics Go to Hydraulic ABS HABS diagnostics WCC Chassis OR Go to Hydraulic Power Brake HPB diagnostics Go to Electronic Leveling Module ELM for Tractors Go to Electronic Leveling Module ELM for Trailers System Setup Select System Setup from the Main Menu Language Select Language from the System Setup menu The default is English To change the default to French or Spanish ABS only 1 Select the appropriate language 2 Click OK to accept the selection W Series Chassis ILES Brakes Click on Select ECU from the System Setup menu then select the type of ABS to be tested Click on the appropriate Meritor WABCO product icon to display the Main Menu for that program Roll Call displays all actively broadcasting ECU s NOTICE TOOLBOX diagnostics cover only Meritor WABCO ECU s COM Port The correct Vendor Protocol and Device selections are essential TOOLBOX will not operate correctly if these selections are not accurate For assistance contact the Workhorse Technical Assistance Center at 877 246 7731 From the System Setup pull down menu select COM Port to display the Devic
73. e Settings menu Current settings will be shown Vendor To change these selections click on the down arrow for a list of vendor choices Select the appropriate vendor Click on the down arrow for the protocol choices Device Click on the down arrow for the device choices Select the device and port to which the data cable is connected Click OK to accept the selections and close the Device Settings window 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 5 Select the Help icon for help using Meritor WABCO TOOLBOX Software Help is accessible from all TOOLBOX pages Search by title or type in a specific topic System Information Help Select System Information and follow the screen prompts to print a report of system hardware operating system version drivers etc Run this report whenever you contact the Workhorse Technical Assistance Center Update Application Versions 5 0 and Higher Select Update Application to download future revisions to TOOLBOX This option is available for TOOLBOX version 5 0 and higher Follow the screen prompts to complete the download About Select About from the pull down menu for information about Meritor WABCO TOOLBOX Software including the version number Hydraulic ABS NOTICE TOOLBOX Software must be connected to the vehi cle and the vehicle ignition must be ON
74. e bleed screw to 14 N m 124 Ib in 6 Install a block of wood into the caliper in front of the caliper pistons CAUTION When removing the pistons from the caliper bore only direct enough compressed air into the caliper brake fluid inlet to ease the pistons out of the bore Do not exceed 25 psi 172 kPa Damage to components will result 7 Apply low air pressure no more than 25 psi 172 kPa to the fluid port in the caliper to move the caliper pistons out to the wood block 8 Remove the pistons Seal and Dust Boot Replacement Meritor Quadraulic Caliper Clean Dry and Inspect Meritor Quadraulic Caliper CLEAN PARTS For ground or polished parts Do not use hot solution tanks or water alkaline solutions to clean ground or pol ished parts Damage to parts will result Use safety solvent or equivalent to clean the surfaces of ground or polished parts For rough metal parts Use a cleaning solvent or weak alkaline solution in a hot solution tank to clean rough metal parts If a hot solution tank is used follow the instructions below 1 Place the rough parts in the hot solution tank 2 Leave the rough parts in the tank until they are completely cleaned and heated 3 Remove the rough parts from the tank 4 Thoroughly wash the rough parts with water until the alkaline solution is completely washed off of the parts DRY AND INSPECT PARTS 1 Use soft clean paper or cloth rags or compre
75. e control module EBCM power up self test This test concludes when the vehicle uses the vehicle speed signal from the PCM in order to reaches a speed greater than 13 km h 8 mph and the calculate the rear wheel speed wheel speeds are verified by the EBCM DTC Descriptors Diagnostic Aids This diagnostic procedure supports the following DTC Thoroughly inspect connections or circuitry that may DTC P0609 Vehicle Speed Output Circuit 2 cause an intermittent malfunction Refer to the following Conditions for Running the DTC Testing for Electrical Intermittents ignition is ON Testing for Intermittent Conditions and Poor Connections The vehicle is not moving Wiring Repairs Connector Repairs Conditions for Setting the DTC Test Description The PCM detects low voltage on the vehicle speed B signal circuit for 45 seconds The numbers below refer to the step numbers on the Action Taken When the DTC Sets diagnostic table If equipped the following actions occur 3 This step tests for a voltage signal from the PCM EBCM disables the ABS TCS DRP 4 This step tests for a missing or erratic vehicle speed Tha ABS indicator tume ON signal from the PCM An assistant may be required The TRACTION OFF indicator turns ON red brake warning indicator turns ON WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual
76. e friction material that has been displaced on the rotor bonds itself to the friction material on the pads After bonding has occurred the rotation of the wheel will cause the bond to break apart or shear This cycle of bonding and shearing is how the brakes stop the vehicle 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SERVICE BRAKE SYSTEM COMPONENTS The hydraulic brake system is made up of the following components Master cylinder reservoir and fluid level sensor Hydraulic brake booster Brake rotors Brake calipers and pads Brake lines and hoses Master Cylinder Reservoir and Fluid Level Sensor The W Series chassis uses a Bosch aluminum master cylinder and plastic brake fluid reservoir The brake fluid reservoir is equipped with a fluid level sensor to alert the driver when the brake fluid level is low Hydraulic Brake Boosters The W Series chassis use two different styles of hydraulic brake boosters Refer to the following table for chassis specific applications Booster Design W16 W18 Bosch Hydro Boost W20 W22 W24 W25 Bosch Hydro Max Bosch Hydro Boost Bosch Hydro Max SECTION pee 5 9 Brakes W Series Chassis Hydro Max Hydraulic Brake Booster The Hydro Max system is utilized on all W20 W22 W24 W25 Series chassis The hydraulic pressure used to operate the power brake booster is norma
77. e in from the edge of the drum TAPER CHECK Measuring a drum for taper involves taking measurements at the inner and the outer edges of the machined surface at two or more places around the drum These measurements should be equal Park Brake Drum Installation NOTICE Refer to Fastener Notice in Cautions and Notices 1 Install the bolts and washers holding the drum assembly to the yoke Tighten the bolts and washers to 58 N m 43 Ib ft Install the parking brake drum and yoke assembly Tighten the bolt to 110 N m 81 Ib ft Install the propeller shaft Refer to Two Piece Propeller Shaft Replacement or Three Piece Propeller Shaft Replacement 6 Adjust the parking brake Refer to Park Brake Cable Service Adjustment T Lower the vehicle cR CO WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 Park Brake Drum Backing Plate Replacement Park Brake Drum Backing Plate Removal 1 Remove the drum Refer to Brake Drum Replacement 2 Remove the linings Refer to Park Brake Shoe Replacement 3 Remove the backing plate mounting bolts and washers 4 Remove the backing plate 5 Remove the anchor pin mounting nut and the anchor pin Park Brake Drum Backing Plate Installation NOTICE Refer to Fastener Notice in Cautions and Notices 1 Install the anchor pin and the anchor pin mounting nut
78. e pull switch shaft 5 Install the pull switch knob retaining pin by using a small hammer and a small drift punch Gently drive the pin in Park Brake Cable Replacement Pedal Type Park Brake Cable Removal 1 Raise the vehicle and support the vehicle with safety stands Refer to Lifting and Jacking the Vehicle in General Information Disconnect the nut from the equalizer Remove the connector Disconnect the cable from the frame bracket Bend the retaining fingers Disconnect the cable from the pedal assembly Remove the retainer clip bolts and the retainer clips Remove the cable assembly Attach a piece of wire to the cable to help in the installation CONDON gt C nh 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 Park Brake Cable Installation 1 Install the cable assembly Ensure the retaining fingers are completely through the holes Bend the retainers back into place NOTICE Refer to Fastener Notice in Cautions and Notices 2 Install the retainer clips and the retainer clip bolts Tighten the retainer clip bolts to 17 N m 13 Ib ft Connect the cable to the pedal assembly Connect the cable to the frame bracket Install the connector Connect the nut to the equalizer Adjust the parking brake Refer to Park Brake Cable Service Adjustment 9 Lower the vehicle CONDO
79. e rest of the cabling all the way to the ECU needs to be checked Brakes STEPB To measure the resistance at the ABS unit through all the cabling and the sensor disconnect the ABS ECU cable from the ECU and connect the ohmmeter from the two sockets in the ECU cable for this sensor e If the reading is not between 900 and 2000 ohms there is an open in the cabling somewhere Refer to the vehicle wiring diagram for connectors and pin outs and then check for continuity from sensor to ECU e If the reading is between 900 and 2000 ohms the sensor and cabling is good Reconnect the ABS ECU and turn on the ignition Use TOOLBOX to check if the fault is still active If it is still active replace the ABS ECU Modulator Assembly Testing Refer to the following graphic when conducting tests on the modulator assembly components Figure 5 45 ABS Modulator Assembly 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION 3 Service Manual 5 9 8 Brakes HARNESS MODULATOR TT CONNECTOR COMMEL I OR PINOUT cucu Oeseipton_ Rumoer n RE 10 Outlet Valve RR Inlet Valve FL je Inlet Valve Open Check Outlzt Valve Fa W Series Chassis WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manu
80. e system 3 Refill the system 4 Bleed the system FLUSHING THE BRAKE HYDRAULIC SYSTEM Flushing the brake hydraulic system involves running new brake fluid through the system and out the open bleeder valves until the fluid runs clear Use Brake Fluid P N 1052535 or an equivalent DOT 3 motor vehicle brake fluid Flush the brake hydraulic system for the following reasons When new hydraulic brake parts are installed When contamination may be present Flushing is the only way to clean contaminated fluid out of the system When you do not know the grade of brake fluid in the brake system When mineral oil is present in the brake fluid W Series Chassis 23 Brakes NORMAL OPERATION NOISES Properly operating Hydro Max and Hydro Boost hydraulic brake boosters may produce certain noises These noises occur for the most part when the brake pedal is manipulated in a manner not associated with everyday driving habits The general categories of normal operating noises are 1 hissing noises and 2 clunk clatter noises The boosters may emit normal hissing noises when above normal brake pedal efforts are applied 40 Ibs and up The hiss sounds particularly noticeable with the vehicle motionless and will increase in intensity as pedal pressure increases above 40 Ibs and system operating temperature increases Loud hissing sounds at or below normal 20 to 25 lbs pedal effort warrants investigation Clunk clat
81. ee Fig 19 Figure 5 18 Upper caliper slide removal CAUTIONS SS SSS Be careful not to damage the boot that pro Figure 5 19 Move caliper away from rotor tects the guide by using the screwdriver in an improper way case of boot s damage it 7 Remove worn pads 9 see Fig 20 is necessary to replace it with a new one 8 Clean the pad supporting area using suitable materials and products e g a damp cloth 5 f you are replacing the caliper on rear wheels with P e g i leaf spring suspension both taken out and the caliper body separated completely Do not use products that could damage the from the bracket seals such as paint thinner mineral spirits gasoline etc CAUTION The operations for retraction of the pistons 9 Check that no damage to the pistons or breakage of described below cause an increase in the the dust covers has occurred brake fluid level in the reservoir Ensure that 10 Open the cap of the brake fluid reservoir and check the fluid does not overflow as it can damage the fluid level the painted parts of the vehicle WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual E 5 41 E Brakes YUSNIA 12 Clean the pad attachment plate using suitable Perform the steps described below with cau materials and products A damp cloth is probably
82. embo 52mm Caliper CLEAN PARTS For ground or polished parts CAUTION a Do not use hot solution tanks or water and alkaline solutions to clean ground or pol ished parts Damage to parts will result PAGE 53 Use safety solvent or equivalent to clean the surfaces of ground or polished parts For rough metal parts W Series Chassis Brakes Use a cleaning solvent or weak alkaline solution in a hot solution tank to clean rough metal parts If a hot solution tank is used follow the instructions below 1 Place the rough parts in the hot solution tank 2 Leave the rough parts in the tank until they are completely cleaned and heated 3 Remove the rough parts from the tank 4 Thoroughly wash the rough parts with water until the alkaline solution is completely washed off of the parts DRY AND INSPECT PARTS 1 Use soft clean paper or cloth rags or compressed air to completely dry parts immediately after cleaning them 2 Carefully inspect each part for wear or damage 3 Repair or replace worn or damaged parts Caliper Piston Installation Brembo 52mm Caliper 1 Install the seals and dust boots Refer to Seal and Dust Boot Replacement Brembo 52mm Caliper 2 Install the pistons in their bores Make sure the lip of the dust boot is seated in the groove in the piston 3 Check the dust boot to determine if there is any air trapped in the dust boot If there is air trapped use a flat blade tool to gently lift t
83. ement and Hub and Rotor Assembly Replacement 3 Remove the bolts that mount the brake rotor to the hub 4 Remove the brake rotor 62 Brakes Brake Rotor Installation NOTICE Any new rotor must have the protective coating removed from the friction surfaces before being placed in service Use Brake Parts Cleaner P N 12345754 or the equivalent and wipe the surface clean with clean cloths Do not use gasoline kerosene or other oil base solvents which may leave an oily residue This residue is damaging to the brake lining and is flammable 1 Install the brake rotor NOTICE Refer to Fastener Notice in Cautions and Notices IMPORTANT Threads must be clean and free of grease Apply 272 Threadlocker P N 12345493 or the equivalent to the threads of each brake rotor mounting bolt 2 Insert the bolts that mount the brake rotor to the hub 3 Tighten the brake rotor to hub bolts e For units with the 9 16 inch OD bolts tighten the bolts to 152 112 Ib ft Forunits with the 5 8 inch OD bolts tighten the bolts to 256 N m 189 Ib ft 4 Install the hub and brake rotor assembly Refer to Wheel Hub Bearing and Seal Replacement Independent or Wheel Hub Bearing and Seal Replacement Beam and Hub and Rotor Assembly Replacement 5 Inspect the brake rotor for runout Refer to Brake Rotor Lateral Runout Check 6 Clean both sides of the rotor with brake cleaner WCC 2007 WorkhorseCus
84. en the parking brake lever to cowl nuts to 25 N m 18 Ib ft Figure 5 37 Cable attachment detail 5 Remove the cotter pin 4 and the washer 5 6 Remove the clevis pin 7 7 Remove the cable to parking brake lever nut and washer 8 Remove the cable to parking brake lever bolts 9 Remove the spacer 1 WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 5 Park Brake Pull Switch Replacement Park Brake Pull Switch Removal d Manually apply parking brake block wheels and turn the ignition OFF before removing any fuses or relays or removing the park brake pull button Figure 5 38 Pull button assembly 1 Disconnect the electrical connector 6 from the back of the pull switch 5 2 Remove the pull switch knob retaining pin by using a small hammer and a small drift punch Gently drive the pin out W Series Chassis 81 Brakes 3 Slide the pull switch knob 1 off of the shaft 4 Remove the pull switch mounting nut 2 and washer 3 5 Remove the pull switch 5 by sliding it out the back of the mounting bracket 4 Park Brake Pull Switch Installation 1 Install the pull switch 5 into the mounting bracket 4 2 Install the pull switch washer 3 and mounting nut 2 3 Tighten the pull switch mounting nut to N m 27 Ib in 4 Install pull switch knob 1 by sliding it onto th
85. er the shoes at the center of the shoes 4 To adjust brake rotate the starwheel until the shoes touch the caliper jaws It is necessary to move the adjuster lever away from the starwheel NOTICE During adjustment the calipers should be moved up and down around the shoe center points to ensure adjust ment at the highest points on the shoes ADJUSTMENT WITH DRUM ON ALTERNATE PROCEDURE CAUTION Always block vehicle to prevent vehicle move ment such as with suitable wheel chocks Failure to do this could result in personal injury or property damage 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 7 5 1 With the engine off and the battery disconnected place transmission in gear and fully release the parking brake Verify that the drum can be rotated by hand If the drum cannot rotate it will be necessary to raise the rear wheels off the ground in order to allow rotation of the drum To raise the rear wheels put the vehicle transmission in gear block the front wheels raise the rear wheels off the ground and support the vehicle with suitable floor stands 2 Insert a brake adjusting tool or flathead screwdriver through the adjusting slot and move the teeth down ward to expand the brake shoes outward Continue expanding the shoes until the drum can not be rotated 3 Now adjust the teeth upward to retract the shoes until the drum ju
86. ere are two types of park brake systems Lever actuated Automatic apply Chassis Model GVWR Ibs Brake System Option W16 16 000 Foot operated STD W18 w LQ4 18 000 Foot operated STD W18 w L18 Automatic apply J72 W20 20 700 Foot operated STD W22 22 000 Foot operated STD W24 W25 24 000 Automatic apply J72 W42 9 400 14 500 Foot operated STD W52 19 500 Foot Operated STD The lever actuated parking brake system is mechanically operated by a lever and strut or a pedal which will activate the drum style transmission mounted propshaft drum brake The automatic apply parking brake is an electro hydraulic system This style of parking brake is spring applied and hydraulically released via an electro hydraulic pump 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 66 Brakes LEVER ACTUATED PARK BRAKE SYSTEM RESERVOIR PRESSURE COMPONENTS TRANSDUCER The lever or pedal actuated park brake system uses the following components Park brake lever either foot or hand apply Cable e Transmission mounted park brake mechanism Park brake lever position switch AUTOMATIC APPLY PARK BRAKE SYSTEM COMPONENTS CAUTION Manually apply parking brake and turn off your ignition before removing any fuses or relays from the vehicle Failure to do so could result in the vehicle moving unexpe
87. estart the icon check if Select the Valve Activation icon or select Component there are any faults existing or stored If there are Tests then Valves to use the pull down menu This write down fault codes and then clear fault code s displays the Valve Activation screen WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual 8 If retarder relay box is checked then go through steps 2 through 7 again Steps may have to be repeated a couple of times before WABCO con zu troller learns there is no retarder relay installed on the vehicle Once the controller learns there is no retarder relay the box will remain unchecked af retarder relay box remains unchecked then pro ceed to step 10 If it still remains checked after going through steps 2 7 then proceed to step 9 9 If the WABCO HABS diagnostic screen is still show ing the retarder relay box checked then check pin cavity 7 in the J1 connector at the WABCO ECU In the 2006 electrical schematics for W 16 W 18 W42 the electrical schematics will show that there is no wire in pin cavity number in the J1 connector Make sure there is no wire in that pin cavity number 7 in the J1 connector 10 Test drive vehicle to make sure fault code s do not return SECTION W Series Chassis 5 92 Brakes apat Figure 5 47 Actuate Miscellaneous Output Screen
88. f the dust boots with brake grease CAUTION D t hot solution tank t d Install the dust boots in the caliper o not use hot solution tanks or water an alkaline solutions to clean ground or pol 5 Install the caliper pistons Refer to Caliper Piston CLEAN PARTS ished parts Damage to parts will result Replacement Brembo 68mm Caliper 6 Install the caliper Refer to Caliper Replacement Use safety solvent or equivalent to clean the surfaces of Brembo 68mm Caliper round or polished parts E rough pond pes Seal and Dust Boot Replacement Bosch ZOH T Caliper Use a cleaning solvent or weak alkaline solution in a hot Seal and Dust Boot Removal Bosch ZOH T Caliper solution tank to clean rough metal parts If a hot solution 1 Remove the caliper Refer to Caliper Replacement tank is used follow the instructions below Bosch ZOH T Caliper 1 Place the rough parts in the hot solution tank 2 Remove the caliper pistons Refer to Caliper Piston 2 Leave the rough parts in the tank until they are Replacement Bosch 2 Caliper completely cleaned and heated 3 Remove the dust boots 3 Remove the rough parts from the tank 4 Remove the seals 4 Thoroughly wash the rough parts with water until the alkaline solution is completely washed off of the parts DRY AND INSPECT PARTS 1 Use soft clean paper or cloth rags or compressed air to completely dry parts immediately after cleaning them 2 Careful
89. f the feed hose at the prescribed torque Remove the spacer previously positioned inside the vehicle cab thus releasing the brake pedal and allowing the pedal to move Loosen the connection between the rubber brake hose and the steel line removing any twist or distortion in the hose Tighten at the prescribed torque Bleed the system Pump the brake pedal repeatedly to move the pistons out until the pads are pressed against the rotor Continue pumping the brake pedal until pedal force returns to normal and the normal stroke is restored Check the brake fluid level in the reservoir and refill as necessary Have an assistant press and hold the brake pedal While the system is under pressure check all of the brake fittings lines and hoses for possible fluid leaks Re check the brake fluid level in the reservoir Add fluid if necessary CAUTION If there are fluid leaks from the caliper repeat all the above operations to ascertain the cause and correct the fault WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 Caliper Piston Replacement Brembo 68mm Caliper Caliper Piston Removal Brembo 68mm Caliper 1 Remove the brake pads Refer to Brake Pad Replacement Brembo 68mm Caliper 2 Remove the caliper Refer to Caliper Replacement Brembo 68mm Caliper 3 Use disc brake pad spreader tool to press both pistons back into
90. f the score 3 Zero the scale 4 Back out the tool bits WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION m 9 5 Advance the cutter hand wheel until the bits have cleared the inner edge of the brake rotor face 6 Adjust the micrometer knobs for approximately 0 0127 mm 0 005 in more than the first reading This will ensure clearing the brake rotor in one cut 7 Perform one cut procedure For refinishing information refer to the Brake Lathe Specifications ACCU TURN 8 Perform swirl refinishing to the brake rotor Refer to Non Directional Refinishing below 9 Remove the brake rotor from the brake lathe 10 Clean the brake rotor using brake cleaner Brake Lathe Method 1 Mount the brake rotor to the brake lathe Refer to the brake lathe manufacturer s recommended procedure 2 Locate the deepest score 3 Turn the brake rotor micrometer knobs until the tool bit bottoms out at the deepest point of the score 4 Zero the scale 5 Back out the tool bits 6 Advance the cutter hand wheel until the bits have cleared the inner edge of the brake rotor face 7 Perform rough and finish cuts For refinishing information refer to the Brake Lathe Specifications AMMCO 8 Perform swirl refinishing to the brake rotor Refer to Non Directional Refinishing below 9 Remove the brake rotor from the brake lathe Clean the br
91. fluid leaks 6 Check the brake fluid level in the reservoir Add fluid if necessary Caliper Piston Replacement Meritor Quadraulic Caliper Caliper Piston Removal Meritor Quadraulic Caliper 1 Remove the caliper Refer to Caliper Replacement Meritor Quadraulic Caliper 2 Loosen the bleed screw but do not remove it 3 Place one end of a hose on the tip of the bleed screw and the other end in a container to catch the brake fluid as it drains 4 Use disc brake pad spreader tool to press both pistons back into their bores which will force the brake fluid out of the caliper 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 W Series Chassis 59 Brakes Remove the dust boots and the piston seals Refer to CAUTION While pressing the pistons back into their bores be careful to not damage the insulat ing ring and the dust covers The dust covers must not be twisted or allowed to trap air If air becomes trapped in the dust cover use a flat blade to gently lift the edge of the seal to release the air CAUTION BERNER Do not place your fingers in front of the pis ton in an attempt to catch or protect it when applying compressed air This could result in serious injury CAUTION To prevent serious personal injury always wear safe eye protection when you perform vehicle maintenance or service 5 Tighten th
92. gear to the Hydro Max inlet Hydro Max inlet port utilizes a tube arrangement 1 JEBE AHO ni T ASSEN ELY En X2 p Ha LEES VALVE SEAT 422 4150 Figure 5 5 Tube Fitting and O ring Seal 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 5 TOC OR Cem Figure 5 7 Outlet Port W Series Chassis 17 Booster Fluid Source Brakes The booster is designed to perform in a flow range of 3 2 to 5 0 gpm Flow rate through the booster can impact vehicle stopping distance therefore the technician may be required to determine the minimum flow rate if poor brake performance is indicated Flow rates below 3 2 gpm can cause slower response times when the booster is applied Flow rates higher than 5 0 gpm may contribute to the booster self applying which will cause brake drag or fluid overheating The power steering pump must be capable of supplying 1 000 psi to the booster plus any additional pressure required by other devices in the system such as a power steering gear Pedal Stop and Proper Spring Load The pedal stop must be adjusted such that when the brake pedal is fully released there is no load on the grommet that retains the pedal rod to the Hydro Max booster When the brake pedal is fully released the spring load must not be greater than that required to support the pedal weigh
93. he affected wheel will be disabled and will return to normal braking The other sensed wheels will retain their ABS function ANTILOCK BRAKE SYSTEM ABS COMPONENTS The antilock brake system is made up of the following components e Electronic Control Unit ECU e Modulator assembly e Wheel speed sensors e Sensor spring clip e Tooth wheel e ABS indicator lamp ABS Electronic Control Unit ECU NOTICE oo Figure 5 39 WABCO ABS Electronic Control Unit ECU Do not open the ECU Opening the ECU to gain access to the internal components will void the warranty Modulator Assembly The ECU processes sensor signals and generates The modulator assembly houses the ABS solenoid solenoid valve commands The commands are usedto control valves one inlet valve and one outlet valve per reduce maintain or reapply brake pressure wheel a pump motor and two accumulators Mounting locations vary depending upon the chassis The assembly contains brake fluid and must be handled Refer to the vehicle specifications for the exact location with appropriate care It should not be exposed to impact All Workhorse chassis use the frame mounted style loads excessive vibrations or compressed air blown into control module the hydraulic ports WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series Service Manual 88 Brakes Sensor Spring Clip WORKHORSE CUSTOM CHASSIS W Series Chassis 9 This c
94. he edge of the dust boot to release the air 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 CAUTION Incorrect positioning of the dust boots will seriously damage the caliper and affect cor rect operation 4 Tighten the bleed screw on the caliper and tighten to the prescribed torque 5 Install the connector of the brake hose to the caliper by rotating the caliper itself 6 Put the caliper body on the bracket tightening the top guide pin to the prescribed torque Be careful not to damage the boots 7 Install the pads in the caliper If reusing the brake pads ensure that the arrows applied before disassembly are pointing in the correct direction CAUTION Ensure that the friction surfaces do not become dirty with grease if necessary all traces of grease must be removed with sand paper CAUTION The pads must be inserted with the friction material facing the disc Incorrect positioning of the pads will affect braking performance and seriously damage the caliper 8 Rotate the caliper body on the top guide pin until it is repositioned on the disc PAGE W Series Chassis ab Brakes 9 Install the lower guide pin tightening the bolt to the 10 11 12 13 14 15 16 17 18 prescribed torque Install the new protective caps carefully cleaning the seats Tighten the connector o
95. he following problems e Brake system contamination e Corrosion e Deterioration of rubber components Brakes Substandard Or Contaminated Brake Fluid NOTICE Power steering fluid and brake fluid cannot be mixed If brake seals contact power steering fluid or steering seals contact brake fluid seal damage will result Use the correct fluids The master cylinder and brake system use brake fluid The hydraulic booster system uses power steering fluid If the brake fluid contains improper fluid water or other contaminants the brake fluid may boil or corrode rubber components in the hydraulic brake system Evidence of rubber deterioration occurs in the following areas e Swollen master cylinder piston seals e Swelling of the wheel cylinder boots e Swelling of caliper boots e Swelling of the master cylinder reservoir diaphragm 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 If you find rubber deterioration replace all rubber parts in the brake system including the hoses Check for brake fluid on the brake linings Replace brake linings that are contaminated with brake fluid If the brake fluid is contaminated and the master cylinder piston seals are good check for leaks and excessive heat conditions If no leaks or excessive heat conditions are found perform the following procedure 1 Drain the brake system 2 Flush th
96. he signals from the transmission and button contacts the ECM closes the solenoid valve and closes the pump motor relay allowing current to flow to the motor The pump motor then supplies fluid to the brake assembly The brake assembly includes a friction disc clamped by a piston through force of an internal spring The fluid pressure acts on the piston overcoming the spring tension that clamps the friction disc releasing the brake The pump motor will shut off when the transducer reads the fluid pressure of approximately 1400 psi The solenoid valve holds pressure in the system while the brake is in a released state The ECM monitors system pressure from the pressure transducer and energizes the pump motor when system pressure drops below approximately 1200 psi Putting the shift lever back to park selecting P on the push button shift control turning off the ignition or pulling the push pull switch prompts the ECM to de energize the solenoid valve dumping fluid back into the reservoir As the pressure decreases the spring force clamps the piston back against the friction disc and applies the park brake 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual TOC Friction Disk Front Housing Cover Reaction Plate Brake Housing 3 7 Rear Housing Cove Bellville Spring pp Figure 5 30 J72 Brake Components W Series Chassis
97. he spool valve channels hydraulic fluid from the power steering pump directly to the power steering gear and lands on the spool valve which block the fluid from entering the boost pressure chamber WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 No internal components of the Hydro Boost booster are serviced separately If an internal failure occurs the booster assembly must be replaced BRAKE FLUID AND BRAKE FLUID HANDLING CAUTION Brake fluid may be irritating to the skin or eyes case of contact take the following actions Eye contact rinse eyes thoroughly with water Skin contact wash skin with soap and water NOTICE Brake fluid will damage electrical connections and painted surfaces Use shop cloths suitable containers and fender covers to prevent brake fluid from contact ing these areas Always re seal and wipe off brake fluid containers to prevent spills Use Brake Fluid P N 1052535 or an equivalent DOT 3 motor vehicle brake fluid Always store brake fluid in a closed sealed container Never use previously opened improperly sealed containers of stored brake fluid Always use new brake fluid or fluid from a properly sealed container PAGE W Series Chassis 22 Re seal brake fluid containers immediately after use Brake fluid left in open or improperly sealed containers will absorb moisture Moisture can lower the brake fluid boiling point causing t
98. heck the wiring X2 7 should go to one end of the retarder relay only Blink Code 73 SAE Fault Code SID 13 FMI 5 Description Retarder Relay Open Circuit The ABS ECU has detected that the retarder relay output is not connected to a load Check the wiring X2 7 should go to one end of the retarder relay Blink Code 73 SAE Fault Code SID 13 FMI 6 Description Retarder Relay Shorted to Ground The ABS ECU has detected a short to ground on the retarder relay output X2 7 Check the wiring X2 7 should go to one end of the retarder relay only 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 Blink Code 74 SAE Fault Code SID 23 FMI 5 Description Warning Light Open The ABS ECU has detected an open circuit on the warning lamp output pin X2 8 Check wiring and bulb This can also be caused by activating the blink code switch for greater than 16 seconds Clear the fault with TOOLBOX software and cycle the ignition If fault repeats replace ABS ECU Blink Code 77 SAE Fault Code SID 54 FMI 4 Description Hydraulic Pump Motor Failure 2 The ABS ECU has detected a failure in the hydraulic pump motor A low level at the motor monitor pin X2 10 has been with the pump motor being activated Check the hydraulic pump and the pump wiring Blink Code 77 SAE Fault Code SID 54 FMI 7 Description Hydraulic Pump Motor Failure 3 Th
99. her wheels The front and rear tire sizes must be within 1496 All tooth wheels must have the same number of teeth 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual Blink Code 52 SECTION SAE Fault Code SID 1 FMI 13 Description Left Front Wheel Sensor Tire Mismatch The ABS ECU has detected wheel speeds that indicate that the tire size or tooth wheel doesn t match the other wheels The front and rear tire sizes must be within 14 All tooth wheels must have the same number of teeth Blink Code 53 SAE Fault Code SID 4 FMI 13 Description Right Rear Wheel Sensor Tire Mismatch The ABS ECU has detected wheel speeds that indicate that the tire size or tooth wheel doesn t match the other wheels The front and rear tire sizes must be within 14 All tooth wheels must have the same number of teeth Blink Code 54 SAE Fault Code SID 3 FMI 13 Description Left Rear Wheel Sensor Tire Mismatch The ABS ECU has detected wheel speeds that indicate that the tire size or tooth wheel doesn t match the other wheels The front and rear tire sizes must be within 14 All tooth wheels must have the same number of teeth W Series Chassis 120 Brakes Blink Code 73 SAE Fault Code SID 13 FMI 3 Description Retarder Relay Shorted to Battery Voltage The ABS ECU has detected a short to battery voltage on the retarder relay output X2 7 C
100. hub bolts Bosch ZOH T Caliper Quadraulic Caliper le alpen 9 16 inch OD 10 bolt pattern Neam Brake shield bolts Brembo 52mm Caliper 19 Ib ft 25 Nem Rotor to hub bolts Bosch ZOH T Caliper Brake shield bolts Brembo 68mm Caliper 19 Ib ft 25 N m 9 16 inch OD 10 bolt pattern 189 Ib ft 256 Brake shield bolts Bosch ZOH T Caliper 19 Ib ft 26 Rotor to hub bolts Meritor Quadraulic Brake shield bolts Meritor Quadraulic Caliper 5 8 inch 5 bolt THREE TIAN Caliper Rotor to hub bolts Meritor Quadraulic Cali 90 Ib ft 122 N m aliper to caliper mounting bracket bolts Caliper 9 16 inch 18 bolt with lock nuts 25 Ib ft 34 Brembo 52mm Caliper WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION 285 5 T Brakes W Series Chassis BRAKE LATHE SPECIFICATIONS Service Manual TOC Rotor to hub bolts Meritor Quadraulic Caliper 9 16 inch 18 with plain nuts 50151 203 Num Splash Shield Bosch ZOH T Caliper 12 16 Ib ft 17 21 Support key bolt Bosch ZOH T Caliper 15 Ib ft 20 BRAKE SYSTEM SPECIFICATIONS Rotor thickness discard Brembo 52mm Caliper Description English Metric Brake Pad minimum thickness above metal discard Brembo 52mm Caliper Hirt Brake Pad minimum thickness above f metal discard Brembo 6
101. icle Pulls to One Side Excessive rotor runout or bent rotor Bad or excessively loose wheel bearings Check rotor with dial indicator Install new rotor if runout exceeds maximum specified Adjust or replace bearings as needed Leaky Caliper Poor quality brake fluid Weak brake hose that expands under pressure Drain and clean system Replace with recommended brake fluid Replace defective hoses Condition Cylinder bore surface scored or corroded Suggested Correction Disassemble calipers clean bore and replace seals and boots Brake Noise Diagnosis Chatter Caliper piston seal damaged or worn Disassemble calipers and install new seals and boots Caliper piston damaged Replace piston Condition Excessive lateral runout of rotor Suggested Correction Check the runout with a dial indicator Install new rotor if the runout exceeds the maximum specified Lack of rotor parallelism Check the parallelism with a micrometer Resurface or install new rotor as required Loose wheel bearing Readjust the bearing to specified torque WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual Brake Noise Diagnosis Scraping SECTION m 9 W Series Chassis 28 Brake Noise Diagnosis Squeal Brakes Condition Rust or mud build up on e
102. imize fluid loss and prevent the entry of contaminants into the system 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 3 Remove the parking brake drum and yoke assembly mounting bolt and washer 4 Remove the brake drum and yoke assembly 5 Remove the yoke from the drum assembly 6 Inspect the yoke ears for damage and the splines for the following damage Wear Burrs Twisting Inspect When you remove the drum brake thoroughly clean and inspect the drum for the following problems Cracks Deep grooves e Scores Out of round SURFACE FINISH Slight scoring can be cleaned up with a fine emery cloth Heavy or extensive scoring causes excessive brake lining wear The drum braking surface will need machining to remove these scores If the drum is grooved and the brake linings are slightly worn do not machine the drum Instead polish the drum braking surface with a fine emery cloth Eliminating all of the drum grooves and the ridges on the lining would require removing too much metal and lining material The grooves and the ridges match and satisfactory service can be obtained by leaving them alone W Series Chassis 83 Brakes INSIDE DIAMETER CHECK Measure the inside diameter of the brake drum at two or more places around the circumference of the braking surface The measurements must be made at the same distanc
103. in order to dis play information W Series Chassis Brakes Hydraulic ABS Menus and Toolbars Select Hydraulic ABS from the TOOLBOX Main Menu TOOLBOX will recognize the HABS or Hydraulic Power Brake HPB ECU and display the appropriate screen If you are working with HPB refer to the HPB section of this manual The Main Screen provides icons and pull down menu task selections It also provides information about the current status of Meritor WABCO HABS ECU information is read once from the ECU and does not change All other information e g wheel sensors voltages and fault information is read and updated continuously NOTICE Double click on Yes in the Existing or Stored Faults fields of the HABS Main Screen to bring up the Fault Information screen Service Information may also be observed from this screen From the Main Screen you can select Restart Exit or Help Tractor ECU Use for all Workhorse chassis Select Tractor ECU from the HABS Main Screen A pull down menu will appear Restart Select Restart to refresh update ECU information Exit Select Exit to exit HABS and return to the TOOLBOX Main Menu 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 5 Select Display from the HABS Main Screen A pull down menu will appear Faults Display Select Faults to display the Fault I
104. install and run TOOLBOX Software on Windows NT 64 MB RAM Approximately 10 0 MB hard disk space for each program 60 MB hard disk space for full install CD ROM drive RS232 to SAE J1708 or RS232 to PLC converter cable e Serial Port RS232 SAE J1708 interface adapter required Follow the instructions included with TOOLBOX Software to install the program on your computer The installation screen offers three types of installations Typical Compact Custom Select Typical or Compact to install tractor trailer and hydraulic ABS diagnostic programs Select Custom to install only one or two of these programs After installation Meritor WABCO TOOLBOX Software will be available on your desktop as an icon and under the Windows start menu NOTICE An RS232 to J1708 or RS232 to PLC converter box attached to the communications port on your comput er COM1 or COMO is required Converter boxes that have been tested and proven satisfactory are Noregon Nexiq B amp B Devices Kent Moore and Dearborn Group 1 Attach the RS232 to J1708 converter cable from your computer s serial port to the converter box 2 Attach the diagnostic cable Deutsch to the vehicle WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 5 At start up select the TOOLBOX Software icon from Desktop or from the Windows Start Menu to display th
105. inum unit The system uses a conventional front to rear brake split The primary piston provides fluid pressure to the front brakes The secondary piston provides fluid pressure to the rear brakes If pressure is lost in either system the remaining system is capable of stopping the vehicle Reservoir and Cover The reservoir is made of plastic Two clips snap the cap onto the reservoir A diaphragm between the cover and the reservoir keeps contaminants out of the brake fluid Keep the master cylinder reservoir properly filled with brake fluid This ensures adequate reserve brake fluid and prevents air from entering the hydraulic system Do not over fill the reservoir The brake fluid absorbs heat from the brakes and expands An over filled reservoir cannot allow fluid expansion Power Steering Pump The power steering pump supplies the Hydro Boost unit with hydraulic pressure the same way the engine manifold vacuum supplies power to the vacuum boost system The pump which is driven by the engine also supplies hydraulic pressure to the power steering gear 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual Power Piston and Accumulator SECTION W Series Chassis 5 19 Brakes The accumulator stores hydraulic fluid under pressure If the power steering pump fails this reserve pressure The Hydro Boost unit contains a valve a power allows at
106. ion shoe Remove the wheel and tire assembly from the Installation axle 4 Remove the sensor from the mounting block in the axle housing Use a twisting motion if necessary Do not pull on the cable 5 Disconnect the sensor cable from the chassis harness 6 Remove the sensor cable from any cable clamps or clips 1 Connect the sensor cable to the chassis harness 2 Install the fasteners used to hold the sensor cable in place 3 Apply a Meritor WABCO recommended lubricant to the sensor spring clip and sensor 4 Install the sensor spring clip Make sure the spring clip tabs are on the inboard side of the vehicle WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series SECTION 5 WORKHORSE CUSTOM CHASSIS Service Manual 108 7 Remove the sensor spring clip from the sensor bracket Spring Clip Installation Direction Mounting Bracket Figure 5 47 Typical Rear WSS Installation Speed Sensor W Series Chassis 1 02 Brakes Installation 1 Connect the new sensor cable to the chassis harness 2 Press the sensor spring clip into the sensor bracket located on the rear axle until it stops Make sure the tabs are on the inboard side 3 Apply a Meritor WABCO recommended lubricant to the sensor 4 Push the sensor completely into the spring clip until it contacts the tooth wheel 5 Re attach the sensor cable to the cable clamps or clips 6 Fasten the sensor cable w
107. it touches the tooth wheel Check sensor and cabling for intermittent contact Blink Code 42 SAE Fault Code SID 1 FMI 2 Description Left Front Wheel Sensor Measurement Not Correct The ABS ECU has detected an incorrect measurement across the sensor on the X3 connector pins 5 and 8 Check electrical resistance of the sensor and the wiring at the ECU and at the harness plugs Check for a broken wire a short to battery voltage or a short to ground Blink Code 42 SAE Fault Code SID 2 FMI 2 Description Right Front Wheel Sensor Measurement Not Correct The ABS ECU has detected an incorrect measurement across the sensor on the X3 connector pins 4 and 9 Check electrical resistance of the sensor and the wiring at the ECU and at the harness plugs Check for a broken wire a short to battery voltage or a short to ground 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual Blink Code 42 SECTION SAE Fault Code SID 1 FMI 10 Description Left Front Wheel Sensor Speed Drop Out The ABS ECU has detected a temporary loss of wheel speed signal Adjust the air gap by pushing the sensor all the way until it touches the tooth wheel Check sensor and cabling for intermittent contact Blink Code 43 Blink Code SAE Fault Code SID 4 FMI 2 Description Right Rear Wheel Sensor Measurement Not Correct The ABS ECU has detected an incorrect measuremen
108. ith tie wraps every 12 inches Properly bundle and store excess cable in the sub frame 7 Replace the tire remove the safety stands lower the vehicle and remove the chocks from the front tires 8 Perform a voltage output check to ensure proper installation Refer to Sensor Output Voltage Test in this section Modulator Assembly Modulator Assembly Removal CAUTION The modulator assembly contains hydraulic brake fluid a caustic substance Remove the valve carefully so that fluid does not leak and cause skin irritation or damage to compo nents 1 Apply the parking brakes Chock the front and rear tires to prevent vehicle movement WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 2 Place a container under the modulator assembly to catch leaking brake fluid 3 Disconnect the electrical harness connectors from the modulator assembly 4 Mark the six brake lines for ease of installation Disconnect the lines from the modulator assembly 5 Remove the three mounting capscrews washers and nuts that attach the modulator assembly and bracket assembly to vehicle NOTICE Whenever any hydraulic system fitting is loosened or disconnected the entire system must be bled to remove any air that may have entered 6 Remove the modulator assembly and bracket Modulator Assembly Installation 1 Position the modulator assembly
109. least two brake applications before complete piston and an accumulator When the valve is moved by of power assist The accumulator serves the same the brake pedal linkage hydraulic pressure is applied function as the vacuum reservoir in the vacuum boost to the power piston The pressure forces the power system The difference is that an accumulator stores piston to move forward toward the master cylinder The hydraulic pressure and a vacuum reservoir stores movement of the piston causes the output rod to operate vacuum pressure The accumulator has a piston which the master cylinder When the brake pedal is pushed compresses nitrogen gas as the reserve chamber fills harder more hydraulic pressure is applied to the piston and the brakes are applied harder High pressure exist the accumulator circuit with the engine turned off This can be extremely dangerous 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual m 5 20 Brakes Steering Gear Accumulator Power Steering Pump Master Cylinder Hydro Boost Assembly Figure 5 8 Hydro Boost System Design Braking Position The hydraulic pressure in the booster pressure chamber forces the piston forward actuating the master cylinder When the brake pedal is pressed the pushrod moves piston the ratio lever which starts the movement of the spool valve This
110. lide areas NOTICE Figure Caliper removal Make sure the brake hose is not twisted or kinked after 13 Inspect the inside of the caliper assembly for signs of installation Damage to the hose could result fluid leakage 2 Align flat on upper top guide pin head with the flat on 14 After the caliper has been removed from the anchor caliper housing upper top guide pin boss Be careful plate remove contamination dirt and debris from the when positioning caliper over the disc brake pads exterior of caliper machined faces and around the rotor and upper top guide pin head to avoid tearing caliper piston boots Clean the machined surfaces of cutting or dislodging piston boots or guide pin boots the anchor plate and caliper with a wire brush 3 Install upper top mounting bolt FINGER tight securing the caliper to the anchor plate 4 Align the flat on the lower pin flange and then carefully 1 Lubricate the caliper and anchor plate sliding surfaces rotate the caliper closed and install lower mounting with silicone brake grease bolt FINGER tight Brake Caliper Installation WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION 8 W Series Chassis Service Manual 5 3 8 Toc Definition of Anchor Plate LEADIMG and TRAILING Position Latag bia n Poma i f 1 Ede Susan s CR a E m a 1 a e is 4 Ed E au i 1
111. lip 1 retains the WSS in the mounting bracket 2 and holds it in close proximity to the tooth wheel Figure 5 41 Typical wheel speed sensor installation Figure 5 40 WABCO Hydraulic Control Unit HCU Tooth Wheel Wheel Speed Sensors Each wheel is equipped with a machined or stamped ring that is mounted to a machined surface on the hub Each wheel is equipped with a wheel speed sensor 4 that is used to measures the speed of a tooth wheel rotating with the vehicle wheel The sensors produce an output voltage proportional to wheel speed WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS ui 89 W Series Chassis Service Manual 5 Once you TOOLBOX software installed on your computer use it to identify system faults Then follow the on screen repair information to make the necessary repairs or replacements To display ABS faults use the pull down menu or the HABS icon to select HABS Hydraulic ABS from the Main Menu Figure 5 42 Tooth wheel ABS Indicator Lamp Figure 5 43 TOOLBOX Pull Down Menu Located on instrument panel it is used to alerts the driver to an ABS system fault ABS DIAGNOSTIC PROCEDURES System Diagnostics Use Meritor WABCO s PC based diagnostic program TOOLBOX Software to diagnose hydraulic ABS faults TOOLBOX software is available for download by Workhorse dealers on the WOW system WCC
112. lly supplied by the power steering pump If fluid flow is not available form the pump the booster s electric backup pump operates to supply the required braking force Hydraulic pressure is monitored when the brake is applied If hydraulic pressure is not available from the power steering pump engine is off the backup pump is activated to provide hydraulic pressure for normal brake operation During normal system operation fluid flow from the power steering pump enters the inlet port of the Hydro Max booster flows through the power piston around the throttle valve and through the flow switch exiting through the outlet port Refer to the illustration on the following page Force applied to the brake pedal by the vehicle operator is multiplied by the lever ratio of the pedal mechanism to move the pedal rod of the booster This movement closes the throttle valve which restricts flow This restriction of flow which results in a pressure increase acting on the power piston applies an amplified force to the master cylinder primary piston A reaction piston inside the power piston subassembly provides the driver pedal feel during an application of the brake pedal Fluid flow through the flow switch opens the backup pump electrical circuit during normal operation 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 TOC A separate check va
113. lowing electri cal schematic is provided here for reference only Circuit numbers may not match actual Workhorse circuits ABS Blink Code Switch Workhorse motor home and commercial chassis do not utilize the optional blink code switch All diagnostics should be performed using the TOOLBOX software as described in this section Wheel Speed Sensor Adjustment On steering axles the sensor is accessible on the in board side of the steering knuckle while on drive axles the sensor is accessible on the in board side of the rear axle spindle W Series Chassis 96 To adjust the sensor push the sensor in until it contacts the tooth wheel IMPORTANT Do not pry or push sensors with sharp objects e Sensors will self adjust during wheel rotation NOTICE No gap is allowable at installation During normal opera tion a gap not to exceed 0 040 inch is allowable Brakes Sensor Output Voltage Test The voltage measured across the sensor output must be at least 0 2 volts AC when the wheel is turned at 30 RPM Test the sensor output voltage as follows 1 Turn the ignition off Block the wheels to prevent the vehicle from moving Support the vehicle with safety stands Do not work under a vehicle sup ported only by jacks Jacks can slip and fall over Serious personal injury can result 2 Raise the vehicle off the ground 3 Disconnect the appropriate connector from the ECU Sensor Pins G707 Gree
114. lution tank to clean rough metal parts If a hot solution tank is used follow the instructions below 1 Place the rough parts in the hot solution tank 2 Leave the rough parts in the tank until they are completely cleaned and heated 3 Remove the rough parts from the tank 4 Thoroughly wash the rough parts with water until the alkaline solution is completely washed off of the parts DRY AND INSPECT PARTS 1 Use soft clean paper or cloth rags or compressed air to completely dry parts immediately after cleaning them 2 Carefully inspect each part for wear or damage 3 Repair or replace worn or damaged parts 58 Brakes Caliper Piston Installation Bosch ZOH T Caliper 1 Install the seals and dust boots Refer to Seal and Dust Boot Replacement Bosch ZOH T Caliper 2 Install the pistons in their bores Make sure the lip of the dust boot is seated in the groove in the piston 3 Check the dust boot to determine if there is any air trapped in the dust boot If there is air trapped use a flat blade tool to gently lift the edge of the dust boot to release the air 4 Pump the brake pedal repeatedly to move the pistons out until the pads are pressed against the rotor Continue pumping the brake pedal until pedal force returns to normal and the normal stroke is restored 5 Have an assistant press and hold the brake pedal While the system is under pressure check all of the brake fittings lines and hoses for possible
115. lve in the backup pump prevents back flow through the pump during normal power applications In the event normal flow from the power source is interrupted the backup pump provides the power at a reduced rate for stopping Upon flow interruption the integral flow switch closes energizing a relay providing electrical power to the backup pump During backup operation the pump re circulates fluid within the booster assembly with pressure built on demand via the throttle valve Fluid is retained within the booster by the inlet port check valve Figure 5 1 Hydro Max Booster and Master Cylinder W Series Chassis 1 0 Brakes MASTER CYLINDER In the released position refer to the illustration on the following page actuators of both the primary and secondary pistons are in with their respective compensating valve stems which project into the cylinder bore This contact tilts the valves to an open position which allows hydraulic fluid in the reservoir sections to communicate with the primary and secondary pressure chambers Each pressure chamber has a piston actuator subassembly containing a preloaded caged spring and return spring Initial forward travel of the primary piston moves the primary actuator away from its compensating valve permitting the valve to seat Closure of this valve shuts off the passage between the primary pressure chamber and the reservoir section serving the primary chamber WCC
116. ly inspect each part for wear or damage 3 Repair or replace worn or damaged parts WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 Clean Dry and Inspect Bosch ZOH T Caliper CLEAN PARTS For ground or polished parts CAUTION Do not use hot solution tanks or water and alkaline solutions to clean ground or pol ished parts Damage to parts will result Use safety solvent or equivalent to clean the surfaces of ground or polished parts FOR ROUGH METAL PARTS Use a cleaning solvent or weak alkaline solution in a hot solution tank to clean rough metal parts If a hot solution tank is used follow the instructions below 1 Place the rough parts in the hot solution tank 2 Leave the rough parts in the tank until they are completely cleaned and heated 3 Remove the rough parts from the tank 4 Thoroughly wash the rough parts with water until the alkaline solution is completely washed off of the parts DRY AND INSPECT PARTS 1 Use soft clean paper or cloth rags or compressed air to completely dry parts immediately after cleaning 2 Carefully inspect each part for wear or damage 3 Repair or replace worn or damaged parts Seal and Dust Boot Installation Bosch ZOH T Caliper 1 Lubricate the new seals with brake grease W Series Chassis 51 2 Install the new seals in the seats inside the caliper body
117. ly to the transmission housing 7 Remove the brake assembly Installation Procedure NOTICE Refer to Fastener Notice in Cautions and Notices 1 Raise the brake assembly into position and align with the mounting holes in the transmission housing 2 Install the bolts and washers attaching the brake assembly to the transmission housing Tighten the bolts and washers to 89 Ib ft 121 Nm 3 Install the yoke and attaching bolt Tighten the bolt to 89 Ib ft 121 Nm 4 Connect the hydraulic line to the brake assembly 5 Fill the brake actuator reservoir with the specified fluid NOTICE 2006 models are filled with Dexron WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 6 Install the propeller shaft Refer to Two Piece Propeller Shaft Replacement or Three Piece Propeller Shaft Replacement 7 Bleed the park brake hydraulic system See bleeding the park brake in this section 8 Lower the vehicle 9 Test the operation of the park brake CAUTION Always test the park brake before proper operation before returning the vehicle to the customer Park Brake Actuator Assembly Replacement Removal Procedure CAUTION Ensure the park brake is applied before removing the actuator The park brake hydrau lic system operates at high pressure Always relieve pressure by applying the park brake before di
118. m 5 1 2 8 Brakes DTC P0609 Step Values Schematic Reference Antilock Brake System Schematics Connector End View Reference Master Electrical Component List Did you perform the Diagnostic System Check Vehicle Go to Step 2 Go to Diagnostic System Check Vehicle 1 Use a scan tool in order to clear the DTCs 19 km h Go to Step Go to Diagnostic Aids 2 Operate the vehicle at a speed greater than the specified value 12 mph Does the DTC set 1 Turn OFF the ignition 10 V Go to Step 4 Go to Step 7 2 Disconnect from the electronic brake control module EBCM the harness connector containing the vehicle speed signal circuit 3 Turn ON the ignition 4 Use a DMM in order to measure the DC voltage between the vehicle speed signal circuit and a good ground Does the voltage measure greater than the specified value Rai Tm 5 7 V Inspect for poor connections at the harness connector of the EBCM Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs Raise and support the vehicle Refer to Lifting and Jacking the Go to Step 5 Go to Step 7 Vehicle Place the transmission in neutral N Set up the DMM in order to measure the DC voltage between the vehicle speed signal circuit and a good ground Spin the rear wheels as fast as possible by hand for at least 30 seconds and while ensuring the driveshaft is rotating observe the DMM Does the voltage measure within
119. m the brake hose fitting 5 Install the brake hose fitting into the port on the caliper CAUTION When installing the brake hose be careful not to twist or kink the brake hose Make sure that an adequate amount of slack is left in the brake hose to allow the suspension and or steering components to move through the normal range of motion without placing ten sion on the brake hose 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 Toc 6 Tighten the brake hose fitting to 18 5 N m 164 Ib in 7 Bleed the system Refer to Bleeding the Hydraulic Brake System 8 Have an assistant press the brake pedal for at least 30 seconds While the pedal is pressed check the brake lines hoses and fittings for possible fluid leaks Make sure that there are no abnormal pressure drops in the circuit and that the rear brake lights illuminate CAUTION OoOO O OO O O If leaks are found correct the leak before returning the vehicle to service 9 If rotors were cleaned or if a new rotor was installed burnish the pads Refer to Burnishing the Rotor and Pads CALIPER REPLACEMENT BREMBO 68MM CALIPER Caliper Removal Brembo 68mm Caliper 1 Remove the brake pads Refer to Brake Pad Replacement Brembo 68mm Caliper Loosen and remove the brake hose fitting at the caliper Cap the brake line and tie it up and out of the way Rem
120. n Left Front Right Front 3 and 10 Right Rear 4 Raise the vehicle off the ground Put safety stands under the axle 5 Rotate the wheel by hand at 30 RPM 1 2 revolution 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 6 Measure the voltage at the connector sockets If the minimum voltage is less than 0 2 VAC push the sensor in until it touches the tooth wheel and remeasure If it is still too low replace the sensor Sensor output voltage must be at least 0 2 volts AC at 30 rpm Sensor Resistance Test Normally there should be between 900 to 2000 ohms measured between the two pins A resistance measurement should be taken with an ohmmeter Make sure that the ignition is turned off You may start with either Step A or Step B whichever is easiest to access STEPA To measure the resistance at the sensor connector disconnect the sensor from the sensor extension cable Connect the ohmmeter to the two sockets on the sensor cable e If the reading is not between 900 and 2000 ohms replace the sensor Turn the ignition back on and use TOOLBOX to verify that the fault is not active NOTICE The ABS light will not go out until the vehicle has moved and the sensors have detected good signals W Series Chassis 97 e f the reading is between 900 2000 ohms the sensor itself is good Th
121. n The ABS unit has detected an open circuit between the pins that connect to the left front ABS inlet valve on the X1 connector pins 5 amp 2 The open circuit may be caused by a bad solenoid valve or an open in the cable Sockets Use an ohmmeter to check the resistance and determine the bad component Blink Code 24 SAE Fault Code SID 44 FMI 6 Description Left Rear Inlet Valve Shorted to Ground The ABS ECU has detected that the inlet solenoid valve X1 5 is shorted to ground Check the cables from the ECU to the valve for damage Blink Code 24 SAE Fault Code SID 50 FMI 3 Description Left Rear Outlet Valve Shorted to Battery Voltage The ABS ECU has detected that the outlet solenoid valve X1 8 is shorted to battery voltage Check the cables from the ECU to the valve for damage 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 5 Blink Code 24 SAE Fault Code SID 50 FMI 5 Description Left Rear Outlet Valve Open The ABS unit has detected an open circuit between the pins that connect to the left front ABS outlet valve on the X1 connector pins 8 amp 2 The open circuit may be caused by a bad solenoid valve or an open in the cable sockets Use an ohmmeter to check the resistance and determine the bad component Blink Code 24 SAE Fault Code SID 50 FMI 6 Description Left Rear Outlet Valve Shorted to Ground The AB
122. n attempt to catch or protect it when applying compressed air This could result in serious injury prevent serious personal injury always wear safe eye protection when you perform vehicle maintenance or service 5 Tighten the bleed screw to 14 N m 124 Ib in 6 Install a block of wood into the caliper in front of the caliper pistons CAUTION When removing the pistons from the caliper bore only direct enough compressed air into the caliper brake fluid inlet to ease the pistons out of the bore Do not exceed 25 psi 172 kPa Damage to components will result 7 Apply low air pressure no more than 25 psi 172 kPa to the fluid port in the caliper to move the caliper pistons out to the wood block 8 Remove the pistons 9 Remove the dust boots and the piston seals Refer to Seal and Dust Boot Replacement Bosch ZOH T Caliper WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual 5 TOC Clean Dry and Inspect Bosch ZOH T Caliper CLEAN PARTS For ground or polished parts CAUTION Do not use hot solution tanks or water and alkaline solutions to clean ground or pol ished parts Damage to parts will result Use safety solvent or equivalent to clean the surfaces of ground or polished parts For rough metal parts Use a cleaning solvent or weak alkaline solution in a hot so
123. n off for the entire bleed pro cedure energizing the unit during bleeding must be impossible W Series Chassis ICI Brakes 2 Fill the pressure bleeder with new DOT 3 hydraulic brake fluid 3 Follow the manufacturer s instructions to connect the pressure bleeder to the brake master cylinder reservoir 4 Set filling pressure to 20 to 30 psi 1 5 to 2 0 bar 5 Turn on bleed equipment until fluid level in reservoir reaches approximately 0 875 inches 20 mm 6 Release pressure for 3 to 5 seconds Apply pressure for 5 to 10 seconds 7 Repeat Steps 5 and 6 approximately 10 times After releasing the pressure air bubbles should rise up into the reservoir CAUTION Do not let the brake master cylinder fluid get below the minimum level during the bleeding operation Keep the master cylinder reservoir filled with new DOT 3 brake fluid Failure to keep the brake reservoir level above minimum could result in more air entering system making it impossible to effectively bleed the system 8 Bleed the brake system Set filling pressure to 20 to 30 psi 1 5 to 2 0 bar Puta wrench on the brake actuator bleeder fitting Start with the farthest from the modulator typically the right rear then attach a length of clear plastic tubing to the bleeder fitting Make sure the tube fits snugly NOTICE Both the tubing and container must be able to withstand the effects of hydraulic brake fluid
124. n report The booster and the master cylinder use two 2 distinctly different incompatible hydraulic fluids They must not be mixed Using the incorrect fluid will permanently damage the seals and can cause the brakes to malfunc tion BRAKE FLUID TUBING HOSES AND FITTINGS Brake fluid lines tubing and flexible hose transmit fluid under pressure between the master cylinder and the brakes The hoses are the flexible links between wheels or axles and the frame or body The hoses must withstand fluid pressure with minimal expansion and must be free to flex without damage during normal suspension deflection and wheel turns The following SAE specifications or their successors if appropriate W Series Chassis 16 are recommended for consideration as a minimum requirement when outfitting a vehicle with brake fluid tubing hoses and fittings The hoses should conform to SAE J1401 Hydraulic Brake Hose Automotive The tubing should conform to SAE J1047 Tubing Motor Vehicle Hydraulic Brake System The fittings should conform to SAE J516a Hydraulic Hose Fittings or SAE J512 Automotive Tube Fittings NOTICE Contact the Workhorse for specific requirements for individual applications Brakes Booster Fluid Tubing Hoses and Fittings The pressure line that supplies fluid to the booster must be a 1 2 diameter flexible or rigid pressure line conforming to SAE J188 and typically designed to run from the steering
125. nformation screen NOTICE The Fault Information Screen is also accessible from the HABS Main Menu The Fault Information screen contains a description of each fault including the type of fault Active or Stored SID and FMI number Repair instructions for the fault appear at the bottom of the screen For detailed repair instructions click on the fault to display a troubleshooting information sheet Bookmark and Thumbnail tabs at the side of the troubleshooting information sheet provide additional information A sample troubleshooting information sheet appears in the Appendix This screen also provides a link to the appropriate system schematic Faults that occur after the screen is displayed will not appear until a screen update is requested Use the Update button at the bottom of the screen to refresh the fault information table and display a new list of faults After making any required repairs use the Clear Faults button to clear the fault Clear each fault as it is repaired Use the Save or Print button to save or print the fault information data Select Exit to close this screen W Series Chassis 110 Brakes Component Tests Select Component Tests from the HABS Main Screen A pull down menu will appear Valves Select Valves to display the Valve Activation screen The Valve Activation screen lets you activate the four valves the pump and the retarder relay In addition to checking for correct activa
126. nstall the pull springs Install the drum Adjust the parking brake Refer to Park Brake Cable Inspect all parts for discoloration due to stress Service Adjustment Mechanical Park Brake Replace the parts if necessary O Clean the backing plate and hardware o Park Brake Pedal Replacement ine drum Park Brake Pedal Removal Inspect the anchor pin for signs of wear Replace the anchor pin as needed 1 Release the parking brake Replace the brake shoe and lining assemblies 2 Remove the parking brake pedal to cowl mounting whenever the thickness of any lining is worn to within nuts 1 0 76 mm 0 030 in of the shoe For riveted shoe and 3 Remove the cable 2 from the pedal assembly lining assemblies replace when the lining is worn to within 0 76 mm 0 030 in of any rivet head Park Brake Shoe Installation NOTICE Lubricate the shoe pads and adjusting screw threads with a thin coat of Lubriplate P N 1050109 or equiva lent DO NOT ALLOW LUBRICANT TO CONTACT BRAKE LININGS 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual Figure 5 35 Park brake pedal assembly 4 Remove the pedal assembly Park Brake Pedal Installation SECTION 5 W Series Chassis 5 19 Brakes Park Brake Lever Replacement Park Brake Lever Removal 1 Release the parking brake 2 Remove the parking brake pedal t
127. o floor nuts 6 and washers 5 Figure 5 36 Lever style park brake 1 Connect the cable to the pedal assembly 2 Position the pedal assembly and install the bolts NOTICE Refer to Fastener Notice in Cautions and Notices 3 Install the parking brake pedal to cowl mounting nuts 4 Tighten the pedal to cowl mounting nuts to 22 N m 16 Ib ft 5 Adjust the parking brake Refer to Park Brake Cable Service Adjustment Mechanical Park Brake W Series 2007 WorkhorseCustom Chassis All Rights Reserved WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual 5 5 80 Brakes 3 Remove the parking brake pedal to floor bolts 2 and 10 Remove the cable 9 washers 4 11 Remove the lever assembly 6 4 Remove the spacers 3 Park Brake Lever Installation 1 Install the lever assembly Install the cable Install the clevis pin Install the washer and the cotter pin Install the spacer Install the cable to parking brake lever bolt Install the washer and cable to the parking brake lever nut Install the spacers 3 9 Install the washer 4 and the parking brake pedal to floor bolts 2 NOTICE Refer to Fastener Notice in Cautions and Notices gt 10 Install the washers 5 and the parking brake pedal to floor nuts 6 11 Tighten the parking brake to floor nuts to 25 N m 18 Ib ft 12 Tight
128. o the valve for damage Blink Code 23 SAE Fault Code SID 51 FMI 5 Description Right Rear Outlet Valve Open The ABS unit has detected an open circuit between the pins that connect to the left front ABS outlet valve on the X1 connector pins 7 amp 2 The open circuit may be caused by a bad solenoid valve or an open in the cable sockets Use an ohmmeter to check the resistance and determine the bad component 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 9 Blink Code 23 SAE Fault Code SID 51 FMI 6 Description Right Rear Outlet Valve Shorted to Ground The ABS ECU has detected that the outlet solenoid valve X1 7 is shorted to ground Check the cables from the ECU to the valve for damage Blink Code 23 SAE Fault Code SID 51 FMI 3 Description Right Rear Outlet Valve Shorted to Battery Voltage The ABS ECU has detected that the outlet solenoid valve X1 7 is shorted to battery voltage Check the cables from the ECU to the valve for damage Blink Code 24 SAE Fault Code SID 44 FMI 3 Description Left Rear Inlet Valve Shorted to Battery Voltage The ABS ECU has detected that the inlet solenoid valve X1 5 is shorted to battery voltage Check the cables from the ECU to the valve for damage W Series Chassis 116 Brakes Blink Code 24 SAE Fault Code SID 44 FMI 5 Description Left Rear Inlet Valve Ope
129. on into neutral 3 Maintain constant foot pressure on the brake pedal If the pedal slowly sinks to the floor the hydraulic system may have internal leakage external leakage or improperly adjusted components 4 Check the fluid level of the master cylinder A slightly low fluid level in either reservoir can result from normal wear of the front brake lining An abnormally low fluid level indicates a leak in the hydraulic system 5 Perform a visual inspection of the hydraulic system W Series Chassis 25 If you find a leaking component refer to the applicable replacement or overhaul procedure Brakes If you find no external leaks internal leakage may be the cause The master cylinder serviced as an assembly and must be replaced if a leak is present Brake Hose And Pipe Inspection Inspect the brake hoses and the brake pipes at least two times a year for the following conditions Chafing of the outer cover Cracks Road damage Check that all hose and pipe mounting hardware Replace any leaky or damaged hose or pipe Repair any insecure mounting hardware 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION 5 W Series Chassis 26 Brakes Brake Hose and Pipe Diagnosis Service Manual TE DIAGNOSTICS AND TROUBLESHOOTING SERVICE BRAKE SYSTEM Master Cylinder Diagnosis These tests will not find all master cylinder malfunctions
130. on sealed units tighten the wheel bearings to zero end play 8 Fasten a dial indicator to the steering knuckle so that the indicator button contacts the brake rotor surface about 25 4 mm 1 in from the outer edge 9 Set the dial indicator to zero 10 Turn the wheel one complete revolution 11 Observe the runout indicated on the dial 12 The TIR must not exceed 0 13 mm 0 005 in 13 Adjust the wheel bearings Brake Rotor Tolerance During the manufacture of the brake rotor tolerances of the braking surfaces for flatness parallelism and lateral runout are closely held The maintenance of close tolerances on the shape of the braking surfaces is necessary in order to prevent brake roughness or brake pedal pulsation In addition to these tolerances the surface finish must be held to a specified range of 60 Ra roughness or less Controlling the braking surface finish avoids problems of hard pedal application excessive brake fade brake and steering pulls and erratic performance In addition control of the surface finish can improve brake lining life Light scoring of the brake rotor surfaces not exceeding 1 5 mm 0 06 in in depth is normal and not detrimental to brake operation W Series Chassis 30 Brakes BOSCH HYDRAULIC BRAKE DIAGNOSIS IMPORTANT REMINDER The first step in diagnosing any customer complaint is to confirm the customer s complaint and determine which category applies The flow charts show
131. oned they can split with consequent loss of the brake fluid 6 Using a felt pen mark the disc rotation direction on the pads to ensure that they are refitted correctly When the caliper body is moved away the pads may remain attached to the disc due to wear 7 Remove the pads from the caliper 8 Place a spacer inside the cab between the seat and the brake pedal so that the pedal remains depressed throughout the procedure 9 Unscrew completely the caliper feed hose by rotating the caliper 0 Move the caliper body away from the vehicle resting it on a suitable work surface 1 Remove the protection cap on the bleed port open the bleed screw and turn the caliper upside down over a container to allow the fluid still inside to drain out completely 2 Re close the bleed port 3 Place a spacer with dimensions similar to those of the brake disc between the pistons and the outer side of the caliper body Force the pistons from the body by using compressed air from the inlet fitting of the caliper 5 When pressure is introduced inside the caliper the pistons will be pushed out of their seats stopping against the spacer W Series Chassis 47 16 Remove the spacer from the caliper 17 Take the pistons out completely being careful not to damage the external diameter Brakes 2 Damage to the outer surface of the piston will make it unserviceable 18 Release the dust boots from their seats
132. ounted to the inboard end of the hub e A separate ABS reluctor ring bolted to the rotor There are various hub configurations offered to accept the 19 5 inch 495 3 mm eight hole wheels as well as 22 5 inch 571 5 mm 10 hole wheels with the hub piloted or stud piloted system WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 5 BRAKE CALIPERS AND PADS Depending on which W Series chassis is being examined it is possible to encounter several different types of brake calipers and pads Chassis GVWR Ibs Brake System Caliber Option W16 16 000 Brembo 2X68 JM6 W18 18 000 Brembo 2X68 JM6 W20 20 700 Bosch ZOH T 2X66 JL9 W22 22 000 Bosch ZOH T 2X66 JL9 W24 24000 EM 4X70 JM8 Quadraulic Meritor W25 25 500 Quadraulic 4 70 JM8 9 400 W42 10 000 Brembo 2X52 JM3 10 000 W42 14 500 Brembo 2X68 JM6 W52 19 500 Bosch ZOH T 2 66 JL9 Brake Rotor Thickness Variation Check Check thickness variation by measuring the brake rotor thickness at four or more points around the circumference of the brake rotor Use a micrometer calibrated in ten thousands of an inch Make all measurements about 25 4 mm 1 in in from the edge of the brake rotor W Series Chassis 29 A brake rotor that varies in thickness by more than 0 05 mm 0 002 in can cause brake pedal pulsation and or front en
133. ove the four caliper bracket to axle mounting bolts Remove the caliper by lifting it from the mounting bracket 6 Clean up any brake fluid that may have leaked out of the hose or caliper W Series Chassis 35 Clean Dry Inspect Brembo 68mm Caliper Brakes CLEAN PARTS 1 Thoroughly clean the exterior caliper surfaces using a damp cloth DRY AND INSPECT PARTS 1 Use soft clean paper or cloth rags or compressed air to completely dry parts immediately after cleaning them 2 Carefully inspect each part for wear or damage 3 Repair or replace worn or damaged parts Caliper Installation Brembo 68mm Caliper 1 Position the caliper on the mounting bracket 2 Install the four new caliper bracket to axle mounting bolts 3 Tighten to the caliper mounting bolts to 215 N m 160 Ib ft Remove the cap from the brake hose fitting Install the brake hose fitting into the port on the caliper Tighten the brake hose fitting to 24 N m 212 Ib in Bleed the brake system Refer to Bleeding the Hydraulic Brake System 8 Have an assistant press the brake pedal for at least 30 seconds While the pedal is pressed check the brake lines hoses and fittings for possible fluid leaks Make sure that there are no abnormal pressure drops in the circuit and that the rear brake lights illuminate NO Ff 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE C
134. pears in the status box the WABCO controller will at times try to seek out the of this screen retarder relay Vehicles equipped with gasoline engines with the Hydra matic transmissions do not have To activate the ABS valves pump or retarder relay retarder relay If you get a Workhorse vehicle equipped select HABS Hydraulic ABS from the Main Menu The Win er engine and WABCO gonitroilar is displaying a fault code s for a retarder relay the Hydraulic ABS Main Menu will appear WABCO controller has to go through a relearn process The steps are as follows 1 Click on Meritor WABCO PC Diagnostics icon Then select the HABS icon This will display the Meritor WABCO Hyaraulic ABS diagnostic screen 2 With Meritor WABCO Hyaraulic ABS diagnostic screen displayed click on Component Tests 3 Under Component Tests select Reset Memorize 4 Selecting the Reset Memorize will cause the WABCO controller to go through a relearn process During this process it should learn that the retarder relay is not installed 5 Check in the Learned Component box to make sure that the retarder relay box is not checked If the check is still in the box then click in box to deselect xn the check mark ette E 6 Then click on the Restart the ECU icon in the upper ACER aia left corner The icon is two arrows formed in a circu Figure 5 46 Valve Actuation Menu lar pattern TRE 7 After clicking on the R
135. positive B is connected to the booster housing and is used as an optional harness ground The flow switch itself is grounded through the booster housing switch reacts to a loss of master cylinder hydraulic pressure in either side of the split hydraulic system and can illuminate a warning light at the instrument panel When pressure is lost in either the primary or secondary circuit of the master cylinder the switch closes The electrical switch will remain closed until the malfunction is corrected When both systems develop normal pressure the switch will return to center and open the electrical switch circuit The switch has two tabs on a common terminal positive and is grounded through the master cylinder Fluid Level Switch When the fluid reaches a predetermined level low fluid level the switch closes and can illuminate a warning light at the instrument panel The switch has two terminals positive and negative which are interchangeable Chassis Ground The booster and master cylinder assembly must be provided with a ground path that will carry the maximum current of the backup pump 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual m 5 14 Brakes BURRS FLU D hE ETX U H UWES PIh 3 D Dr UrE MET Tea var 4 cP 4x5r Lr L h P
136. ps or wetness may not indicate a leak Brake fluid mixes with water Power steering fluid floats on water 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 Brake Drag Possible Causes of Brake Drag 1 Booster does not return 2 Master cylinder does not return 3 Brake pedal does not return 4 ABS traps pressure 5 Brake hoses and tubes collapsed or kinked 6 Brake caliper does not release Prior to moving master cylinder 1 8 inch away from booster loosen two diagonally opposed nuts that hold the master cylinder to the booster by 1 8 inch Have a power tool ready to loosen the remaining two nuts after the brakes have been applied and released ANTILOCK BRAKE SYSTEM ABS DIAGNOSTICS For diagnostic information related to the ABS system refer to the ABS information included in this section PAGE 32 W Series Chassis Brakes MAINTENANCE AND REPAIR This sub section will discuss and explain specific maintenance and repair procedures SETUP PROCEDURES Prior to beginning any maintenance or repair procedure the vehicle must be prepared before beginning work 1 2 3 Park the vehicle on a level surface Block the wheels to prevent the vehicle from moving Raise the vehicle if required so that the area to be serviced is off of the ground and support the vehicle with safety stands Determine where safety problems ma
137. quired Note the results of the test on the Repair Order for future reference b If the brake does not hold the park brake assembly must be replaced 8 Apply the service brake foot brake then release the park brake 9 Release and reapply the service brake foot brake to relieve any strain in the drivetrain 10 Place the transmission in PARK The auto apply park brake should set 11 Turn the ignition OFF and remove the key 12 If the brake did not hold in step 7 chock the wheels and proceed to the repair instructions WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual m 73 Brakes Park Brake Will Not Release 9 Perform Park Brake ECM Connector Pin Out Diagnostic Tests If the J72 park brake will not release chock the wheels e Pin 1 Check for battery voltage on ECM Pin 1 If no and check the following items voltage is present check the fuse and the circuit 1 Check the fluid level in the reservoir Add fluid if the Pin 2 Disconnect the harness from the ECM Connect level is below the MIN line a test lead from Cavity 2 and ground The pump motor 2 Check the ALT START fuse should operate If not check the relay and motor 3 Check the function of the Auto Park Brake Motor Relay acid by substituting a known good relay of the same type Pin 3 Backprobe cavity 3 and apply the park brake 4 Check the function of th
138. r i T Brakes ra p i Figure 5 15 Definition of Leading Trailing NOTICE 6 Connect the brake hose to the fluid inlet on the caliper Refer to Fastener Notice in Cautions and Notices and torque to specifications Do not allow the brake 5 Torque the mounting bolt as follows line hose to become pinched or kinked Torque leading bolt to 93 107 Ib ft 126 145 7 Bleed the brake system Refer to Hydraulic Brake Torque trailing bolt to 93 107 Ib ft 126 145 Nem System Bleeding 8 Install the tire and wheel assembly Refer to Tire and Wheel Removal and Installation IMPORTANT Before moving the vehicle pump the brake pedal sever al times in order to make sure the pedal is firm Do not move the vehicle until a firm pedal is obtained Check the brake fluid level in the master cylinder after pump ing the brakes 10 Lower the vehicle Figure 5 16 Caliper Mounting Bolt WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 BRAKE CALIPER REPLACEMENT MERITOR QUADRAULIC CALIPER 1 Remove the brake hose hold down clamp bolt if equipped 2 Remove the brake hose tube from the caliper 3 Remove four caliper to support assembly bolts CAUTION Do not disassemble the four bolts joining the two halves of the caliper Disassemble and Overhaul the Brake Caliper 4 Remove the
139. r s side of the radiator core support It monitors the vehicle s ignition switch to turn on off the supply of the fifteen and forty five amp fused lines that the ECM and electric motor use If the relay was not present the ECM would be continually powered since it would be directly connected to the batteries Toc Ignition Relay Actuator Assembly The actuator assembly controls the pressure in the park brake system to either set or release the park brake The actuator consists of a mounting bracket and the following components Electronic Control Module The electronic control module ECM is an analog logic device that monitors the various vehicle conditions then controls the actuator accordingly It is the black box mounted underneath the actuator mounting bracket It connects to the vehicle via a fourteen pin connector to the proportional solenoid valve via a two pin connector and a pressure transducer via a three pin connector The ECM is powered by two different sources First it receives power primarily through a fifteen amp fuse Secondly the ECM receives power off of the forty five amp fused line that the pump motor relay also uses W Series Chassis 70 Brakes Pump Motor Assembly The pump motor assembly consists of an electric motor geared pump aluminum port block and a semi transparent fluid reservoir The port block holds the proportional solenoid valve and pressure transducer The pump provides fl
140. re the resistance at the ABS Modulator Unit itself is good The rest of the cabling all the way to the connector disconnect the valve cable from the unit ECU needs to be checked Connect the ohmmeter across each valve solenoid coil to ground STEP B If the reading is not between 3 0 and 4 0 ohms clean the electrical contacts on the connector and check the resistance again If still out of range replace the ABS valve Turn the ignition back and use TOOLBOX to verify that the fault is not active If the reading is between 3 0 4 0 ohms the valve itself is good The rest of the cabling all the way to the ECU needs to be checked To measure the resistance at the ABS unit through all the cabling and the valve disconnect the ABS ECU cable from the ECU and connect the ohmmeter between the sockets for the solenoid coil in the ECU cable for this valve see table below and ground e f the reading is not between 6 0 and 7 0 ohms there is STEPB WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual x 5 1 00 Brakes To measure the resistance at the ABS unit through all Wheel Speed Sensor Replacement Front Axle the cabling and the valve disconnect the ABS ECU cable from the ECU and connect the ohmmeter between Removal the sockets for the solenoid coil in the ECU cable for this m valve v To serious eye injury
141. read the bleed screw into the port on the caliper 2 Tighten the bleed screw On Brembo 52mm calipers the bleed screw should be tightened to 124 Ib in 14 N m On Brembo 68mm calipers the bleed screw should be tightened to 177 16 in 20 N m On Bosch ZOH T calipers the bleed screw should be tightened to 97 Ib in 11 On Meritor Quadraulic calipers the bleed screw should be tightened to 150 Ib in 17 N m 3 Bleed the brakes Refer to Brake System Bleeding 4 Install the cap on the bleed screw W Series Chassis 46 Seal and Dust Boot Replacement Brembo 52mm Caliper Brakes Seal and Dust Boot Removal Brembo 52mm Caliper 1 Loosen but do not remove the fluid line at the caliper 2 Remove the protective caps 4 of the caliper slide pin guides 6 see Fig 25 Figure 5 25 Removal of the screw of the sliding guides 3 Loosen and remove the caliper slide pins 5 of the sliding guides see Fig 26 4 Remove both the two sliding guides 6 from the caliper bracket 7 using a suitable prybar if required see Fig 26 Figure 5 26 Remove caliper slide pin guides 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 5 TOC 5 Lift the caliper body from the rotor CAUTION 1 1 1 1 14 The brake fluid pipes must remain free not tensioned If the pipes are tensi
142. rly discard hydraulic brake fluid that is removed from the brake system Hydraulic brake fluid that is removed can be contami nated and can cause damage loss of braking and serious personal injury 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 CAUTION Use only the DOT 3 hydraulic brake fluid Do not use or mix different types of hydraulic brake fluid The wrong hydraulic brake fluid will damage the rubber parts of the brake caliper and can cause damage loss of brak ing and serious personal injury CAUTION Hydraulic brake fluid is a caustic substance Contact with hydraulic brake fluid can cause skin irritation Do not let hydraulic brake fluid touch any painted surfaces as it will remove the paint Hydraulic brake fluid may also damage cer tain non metal surfaces Do not let fluid get on brake pads shoes rotors or disks Pressure Fill and Bleed Pressure fill and bleed is the preferred method for bleeding the service brake system It requires the use of a special pressure bleeder kit consisting of a tank pressure pump and valve gauge tubing and adapter These kits are available from a number of manufacturers and include instructions for use Pressure Fill and Bleed Procedure 1 Apply the parking brake and chock the tires Turn the ignition OFF and disconnect the battery terminals NOTICE The ignition must remai
143. s referred to as burnishing Burnishing is the process of displacing brake pad friction material onto the rotor Toc Burnishing the Rotors and Pads Brake power is generated when the friction material that has been displaced on the rotor bonds itself to the friction material on the pads After bonding has occurred the rotation of the wheel will cause the bond to break apart or shear This cycle of bonding and shearing is how the brakes stop the vehicle If the rotors and pads are not burnished properly the efficiency of the braking system will be compromised Typically burnishing occurs during the first 10 50 stops Anytime a rotor is cleaned it will need to be burnished again to deposit the friction material from the brake pads onto the friction surface of the rotors 1 Make 10 stops from 45 mph at an average deceleration rate of approximately 15 ft sec with brake applications at two mile intervals 2 Make six stops from 60 mph at an average deceleration rate of 27 ft sec with brake applications at 15 second intervals NOTICE DO NOT make light pedal applications or ride the brakes before the burnishing process is complete W Series Chassis 65 Brakes PARK BRAKE SYSTEM The parking brake system is a secondary brake system that uses a brake mechanism that is mounted on the tailshaft of the transmission This brake system is used to prevent the vehicle from rolling while the vehicle is parked Th
144. sconnecting any hydraulic fittings 1 Disconnect the electrical connectors from the actuator assembly 2 Disconnect the Hydraulic line from the actuator assembly Cap the actuator fitting and plug the line to prevent fluid loss 3 Remove the bolts attaching the actuator assembly to the bulkhead PAGE W Series Chassis Installation Procedure NOTICE Refer to Fastener Notice in Cautions and Notices Brakes 1 Ensure that the hydraulic fitting is properly tightened in the actuator housing before installing the hydraulic line Tighten the fitting to 108 Ib in 12 Nm 2 Install the new actuator assembly and tighten the bolts Tighten the bolts to 28 Ib ft 38 Nm 3 Connect the hydraulic line to the actuator assembly Tighten the fitting to 108 Ib in 12 Nm 4 Connect the electrical connection to the actuator assembly 5 Fill the fluid reservoir with the appropriate fluid NOTICE 2006 models use Dexron VI in the hydraulic system 6 Bleed the park brake system See bleeding the park brake in this section CAUTION Always test the park brake before proper operation before returning the vehicle to the customer 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 TOC PARK BRAKE SYSTEM DIAGNOSTICS Park Brake System Check NOTICE Use care when probing terminals to measure voltage and resistance values The Digit
145. seal to release the air CAUTION Do not place your fingers in front of the pis ton in an attempt to catch or protect it when applying compressed air This could result in serious injury W Series Chassis 56 Brakes 0 A To prevent serious personal injury always wear safe eye protection when you perform vehicle maintenance or service 2 Use an air nozzle to force compressed air into the caliper through the brake fluid inlet port The compressed air will force the edges of the seals out Insert the piston through the seal Once the leading edge of the piston is through the seal remove the compressed air 3 Press the pistons into the bores Be careful to not damage the seals or the boots Make sure that after the pistons have been installed that the dust boots are properly seated in the seal groove on the piston CAUTION While pressing the pistons back into their bores be careful to not damage the seal and the dust boots The dust boots must not be twisted or allowed to trap air If air becomes trapped in the dust cover use a flat blade to gently lift the edge of the seal to release the air 4 Use a flat blade tool to lift the edge of the boots to release any air that may be trapped inside 5 Install the caliper Refer to Caliper Replacement Brembo 68mm Caliper 6 Install the brake pads Refer to Brake Pad Replacement Brembo 68mm Caliper WCC 2007 WorkhorseCustom Chassis
146. sed air to completely dry parts immediately after cleaning them 2 Carefully inspect each part for wear or damage 3 Repair or replace worn or damaged parts Seal and Dust Boot Installation Brembo 52mm Caliper 1 Lubricate the new seals with brake grease 2 Install the new seals in the seats inside the caliper body Make sure the seals are properly seated before continuing 3 Lubricate the pistons around their outer diameter with brake grease 4 Install dust boot on the caliper 5 Install the pistons Refer to Caliper Piston Replacement Brembo 52mm Caliper 6 Install the caliper Refer to Caliper Replacement Brembo 52mm Caliper Seal and Dust Boot Replacement Brembo 68mm Caliper Seal and Dust Boot Removal Brembo 68mm Caliper 1 Remove the caliper Refer to Caliper Replacement Brembo 68mm Caliper 2 Remove the pistons Refer to Caliper Piston Replacement Brembo 68mm Caliper 3 Remove the dust boots 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual 758 5 50 Brakes 4 Remove the piston seals Seal and Dust Boot Installation Brembo 68mm Caliper Clean Dry and Inspect Parts Brembo 68mm Caliper 1 Lubricate the new seals and the outside diameter of the pistons with brake grease 2 Insert the seals into the seats of the caliper For ground or polished parts 3 Lubricate the inner and outer edges o
147. sert each piston in its seat exerting a uniform and seriously damage the caliper pressure over the whole of the piston face 29 Push each piston into its seat as far as it will go 35 Rotate the caliper body around the main guide until it is repositioned on the disc 30 Check the correct position of the dust boot 36 Reconnect the secondary sliding guide re tightening CAUTION the secondary guide bolt to the prescribed torque Incorrect positioning of the dust boots will 37 Install new protective caps carefully cleaning the seriously damage the caliper and affect cor seats SL 38 Tighten the connector of the feed hose at the 31 Tighten the bleeding screw on the caliper body and prescribed torque close it at the prescribed torque 39 Remove the spacer previously positioned inside 32 Attach the connector of the feed hose to the caliper by the vehicle cab thus releasing the brake pedal and rotating the caliper itself allowing the circuit to re open 33 Put the caliper body on the bracket retightening the 40 Loosen the connection between the brake hose and main sliding guide to the prescribed torque Be careful the steel line allowing any twist or kink in the hose to not to damage the boots straighten Tighten at the prescribed torque NOTICE 41 Bleed the system The main guide is the first guide the disc turns past dur 42 Check every possible fluid leak location press the ing its standard forw
148. sets of pads on the affected axle Seized or frozen pistons Disassemble the calipers to free the pistons or replace the caliper WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual TOC Pedal Pulsation Brake Roughness or Chatter SECTION 5 27 W Series Chassis No Braking Effect or Excessive Pedal Travel Condition Excessive lateral runout of brake rotor Suggested Correction Install a new rotor if runout exceeds the maximum specification Excessive out of parallelism of brake rotor Check the parallelism rotor thickness variation with a micrometer If the rotor thickness variation is within specification resurface the rotor If the rotor thickness is beyond specification replace the rotor Condition Reservoir fluid level low Suggested Correction Check for causes of fluid leak repair as required and refill the reservoir Bleed system as needed Air in the hydraulic system Bleed the system Bleeder screw loose or open Bleed the system and tighten the bleeder screw Caliper piston seal damaged Disassemble the caliper and replace the piston seals Replace piston if damaged Loose or worn steering or suspension parts Replace parts and perform an alignment Excessive front bearing clearance Readjust the bearing to specifications Veh
149. ssed air to completely dry parts immediately after cleaning them WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual 2 Carefully inspect each part for wear or damage 3 Repair or replace worn or damaged parts Caliper Piston Installation Meritor Quadraulic Caliper 1 Install the seals and dust boots Refer to Seal Dust Boot Replacement Meritor Quadraulic Caliper 2 Install the pistons in their bores Make sure the lip of the dust boot is seated in the groove in the piston 3 Check the dust boot to determine if there is any air trapped in the dust boot If there is air trapped use a flat blade tool to gently lift the edge of the dust boot to release the air 4 Pump the brake pedal repeatedly to move the pistons out until the pads are pressed against the rotor Continue pumping the brake pedal until pedal force returns to normal and the normal stroke is restored 5 Have an assistant press and hold the brake pedal While the system is under pressure check all of the brake fittings lines and hoses for possible fluid leaks 6 Check the brake fluid level in the reservoir Add fluid if necessary Caliper Guide Pin and Dust Boot Replacement 52mm Caliper Guide Pin and Dust Boot Removal Brembo 52mm Caliper 1 Remove the caliper Refer to Caliper Replacement Brembo 52mm Caliper 2 Remove the caliper guide pin 3 Remove the dust boot SECTIO
150. ssembly mounting bolts Remove the parking brake pump motor assembly Remove the pressure indicator switch from parking brake pump motor assembly Automatic Apply Park Brake Pump Reservoir Assembly Installation NOTICE Refer to Fastener Notice in Cautions and Notices 1 Co Connect the pressure indicator switch to the parking brake pump motor assembly Tighten the switch to 12 N m 106 Ib in Install the parking brake pump motor assembly 4 Install the parking brake pump motor assembly N mounting bolts Tighten parking brake pump motor assembly mounting bolts to 37 N m 27 Ib ft Install the hydraulic pipes Tighten the hydraulic pipe fittings to 16 N m 12 Ib ft 8 Install the pressure indicator switch electrical 10 11 connector Install the parking brake pump motor assembly electrical connector Install the access panel on the inboard side of the component box Tighten the access panel fasteners to 12 N m 1 06 Ib in 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 5 12 Fill the pump motor reservoir with Dexron III transmission fluid 13 Cycle the system at least six times 14 Turn the ignition switch ON and move the shift lever from Park to Neutral 15 Check the fluid level Refer to Checking and Adding Park Brake Fluid 16 Release the manual Parking brak
151. st begins to rotate freely without drag from the shoes NOTICE To decrease shoe spread it is necessary to insert a thin screwdriver through the adjusting slot in the brake back ing plate and push the adjusting lever away from the starwheel W Series Chassis PARK BRAKE SERVICE MANUAL APPLY PARK BRAKE Park Brake Shoe Replacement Park Brake Shoe Removal 1 Remove the drum Refer to Brake Drum Replacement 2 Remove the pull springs 3 Remove the guide plate 17 Figure 5 34 Park brake components 4 Remove the holder pin spring cups 10 the springs and the washers 5 Remove the shoe lever strut and the spring 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual m 78 6 Remove the shoe lever ring 1 Install the brake shoe adjuster and the spring to both 7 Remove the shoe lever and the washer sides 8 Remove the parking brake shoes 9 Remove the brake shoe adjuster 10 Remove the brake shoe adjuster spring Clean Dry and Inspect CLEAN T DRY AND INSPECT d Inspect the brake drum for scoring and spots Machine Install the parking brake shoes Install the shoe lever and the ring Install the shoe lever strut and the spring Install the holder pin spring washers the springs and the cups 10 Install the guide plates 17 I
152. t The reason for a properly adjusted pedal stop and for the limitation on spring load is to prevent the spring from pulling on the grommet within the Hydro Max booster and damaging the grommet The grommet is not designed to be loaded in this manner 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual TOC SECTION NOTICE Any adjustment of the brake switch and backup pump must not compromise the adjustment of the pedal stop Hydro Max Brake System Diagnosis Refer to the following tables when diagnosing problems with the Hydro Max master cylinder and booster HYDRO BOOST HYDRAULIC BRAKE BOOSTER System Description The hydraulic booster provides power assist using fluid pressure from the power steering pump The Hydro Boost system uses hydraulic pressure from the power steering pump to operate the master cylinder The Hydro Boost unit is located between the master cylinder and the brake pedal The brake pedal is connected to a valve inside the Hydro Boost unit and allows the driver to control brake application The operation of the Hydro Boost unit is similar to the vacuum boost unit except that the Hydro Boost unit uses a hydraulic piston and a hydraulic pressure from the power steering pump to create the force to the master cylinder W Series Chassis 18 Master Cylinder Brakes The master cylinder is an alum
153. t across the sensor on the X3 connector pins 7 and 6 Check electrical resistance of the sensor and the wiring at the ECU and at the harness plugs Check for a broken wire a short to battery voltage or a short to ground Blink Code 43 SAE Fault Code SID 4 FMI 10 Description Right Rear Wheel Sensor Speed Drop Out The ABS ECU has detected a temporary loss of wheel speed signal Adjust the air gap by pushing the sensor all the way until it touches the tooth wheel Check sensor and cabling for intermittent contact W Series Chassis 119 Brakes Blink Code 44 SAE Fault Code SID 3 FMI 2 Description Left Rear Wheel Sensor Measurement Not Correct The ABS ECU has detected an incorrect measurement across the sensor on the X3 connector pins 10 and 3 Check electrical resistance of the sensor and the wiring at the ECU and at the harness plugs Check for a broken wire a short to battery voltage or a short to ground Blink Code 44 SAE Fault Code SID 3 FMI 10 Description Left Rear Wheel Sensor Speed Drop Out The ABS ECU has detected a temporary loss of wheel speed signal Adjust the air gap by pushing the sensor all the way until it touches the tooth wheel Check sensor and cabling for intermittent contact Blink Code 51 SAE Fault Code SID 2 FMI 13 Description Right Front Wheel Sensor Tire Mismatch The ABS ECU has detected wheel speeds that indicate that the tire size or tooth wheel doesn t match the ot
154. t and the brake diagnostic port in the cab of the truck pedal pushes back when you perform an ABS stop 4 Launch Meritor WABCO TOOLBOX Diagnostic Mie svete bigod Prorodure dd Software e f there is no firm pedal resistance check the brake system for defects leaks etc and make the necessary repairs then repeat the bleed procedure WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION 5 The following Blink Codes are designated by two digit number To determine the actual blink code use the following example 23 2 blinks pause 3 blinks Service Manual 108 MERITOR WABCO FAULT CODES NOTICE Blink Code 21 SAE Fault Code SID 43 FMI 3 Description Right Front Inlet Valve Shorted to Battery Voltage The ABS ECU has detected that the inlet solenoid valve X1 4 is shorted to battery voltage Check the cables from the ECU to the valve for damage Blink Code 21 SAE Fault Code SID 43 FMI 5 Description Right Front Inlet Valve Open The ABS unit has detected an open circuit between the pins that connect to the left front ABS inlet valve on the X1 connector pins 4 amp 2 The open circuit may be caused by a bad solenoid valve or an open in the cable sockets Use an ohmmeter to check the resistance and determine the bad component PAGE W Series Chassis 113 Brakes Blink Code 21 SAE Fault Code SID 43 6 Description Right Front
155. t may be necessary to replace the brake rotors in pairs in order to assure an even braking balance on both wheels W Series Chassis 63 Accurate control of brake rotor tolerance is necessary for the proper performance of disc brakes Machining should be done only with precision equipment Service the machining equipment on a regular basis following the manufacturer s recommended maintenance procedures Brakes When refinishing brake rotors make sure the attaching adapters the tool holders the vibration dampeners and the tool bits are in good condition Always use sharp cutting tools or bits Use only the replacement cutting bits recommended by the equipment manufacturer Dull or worn tools leave a poor surface finish that will affect braking performance Always use vibration dampening attachments when refinishing braking surfaces These attachments eliminate tool chatter in order to allow for a better surface finish Make sure these adapters are clean and free of nicks The following are two recommended procedures that achieve adequate results using two different off vehicle disc brake lathes If any other lathe is used follow that manufacturer s instructions and recommendations Accu turn Brake Lathe 1 Mount the brake rotor to the brake lathe Refer to the brake lathe manufacturer s recommended procedure 2 Locate the deepest score and turn the micrometer knobs until the tool bit bottoms out at the deepest point o
156. ter or clicking noises will be heard when the brake pedal is quickly released from hard 50 to 100 lbs pedal efforts 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION 5 If the vehicle pulls to one side during braking do not assume the cause is a brake system malfunction Ensure that the front end alignment is correct before diagnosing the brake system Service Manual m BRAKE SYSTEM TESTING IMPORTANT Test the brakes at different speeds with light pedal pressure and with heavy pedal pressure Avoid locking the wheels Avoid sliding the tires on the roadway Locked wheels and sliding tires do not show brake efficiency A locked wheel and a sliding tire reduce the tire friction on the roadway Heavily braked turning wheels will stop the vehicle in less distance Test the brakes on a dry clean reasonably smooth and level roadway You cannot accurately test brake performance without these conditions The tires will not grip the roadway equally if the roadway is wet or greasy or covered with loose dirt A crowned roadway causes the weight of the vehicle to shift toward one side The wheels bounce on a rough road way The following conditions also affect brake performance Tires with unequal contact and unequal grip on the road will cause unequal braking The tires must be equally inflated The tread pattern of the right tires and the left tires must be about equ
157. testing the ABS system do not damage the connector termi nals WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION 93 W Series Chassis Service Manual 5 Brakes Dee booa Black X Z Connector Gray X 1 Connector Green X 3 Connector Number Description Description Description 12 Battery Left Rear Sensor Right Rear Inlet Valve ABS Indicator Lamp Left Front Sensor and Blink Code Switch RightFrontOutiet Valve 9 Right Front Sensor 15 Left Rear Sensor x lo lI 2 Figure 5 50 ABS Control Module Connectors WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 Standard Component Testing ABS Indicator Lamp If the ABS indicator lamp does not come on after the ignition is turned on or it comes on but does not go out after three seconds check all ABS fuses or circuit breakers and replace if necessary Check the wiring to the ABS diagnostic switch and the indicator lamp and repair or replace the wiring as required When checking the indicator lamp follow these steps 1 Check voltage potential at the lamp socket 2 Check continuity of the wires to the socket 3 Replace the bulb NOTICE A complete wiring diagram for the ABS system is avail able in the vehicle wiring diagram The fol
158. their bores which will force the brake fluid out of the caliper CAUTION While pressing the pistons back into their bores be careful to not damage the seal and the dust boots The dust boots must not be twisted or allowed to trap air If air becomes trapped in the dust cover use a flat blade to gently lift the edge of the seal to release the air CAUTION SSE Do not place your fingers in front of the pis ton in an attempt to catch or protect it when applying compressed air This could result in serious injury To prevent serious personal injury always wear safe eye protection when you perform vehicle maintenance or service 4 Install a block of wood into the caliper in front of the caliper pistons W Series Chassis 55 Brakes When removing the pistons from the caliper bore only direct enough compressed air into the caliper brake fluid inlet to ease the pistons out of the bore Do not exceed 25 psi 172 kPa Damage to components will result 5 Apply low air pressure no more than 25 psi 172 kPa to the fluid port in the caliper to move the caliper pistons out to the wood block 6 Remove the pistons 7 Remove the dust boots and the piston seals Refer to Seal and Dust Boot Replacement Brembo 68mm Caliper Clean Dry and Inspect Brembo 68mm Caliper CLEAN PARTS For ground or polished parts CAUTION Do not use hot solution tanks or water and alkaline solu
159. tion The retraction of pistons can cause enough Make sure that pistons are not damaged and brake fluid to spurt from the tank dust covers are not broken If the fluid comes in contact with painted A 0 Do not use products that could damage the level of fluid in the tank is moderate draining some fluid if necessary seals such as paint thinner mineral spirits gasoline etc 11 Move the pistons backward using a retractor or other suitable tool see Fig 20 13 Clean the braking surfaces of the disc with a degreasing product Brake Pad Installation 1 Install the new pads in the caliper bracket The pads must be inserted with the friction material facing the disc 2 Carefully rotate the caliper body around the tightened sliding guide see Fig 21 Figure 20 Move the pistons backward During retraction of the pistons ensure that you do not damage the dust covers The dust covers must not be twisted or allowed trap air If air is trapped eliminate it lifting it with a special tool without damaging the covers Figure 21 Rotate caliper back onto rotor WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 CAUTION Make sure that the guide covers are not damaged from knocking against the caliper bracket 3 Move the caliper body forward to
160. tion this screen provides an easy way to make sure the valves are wired correctly and that wiring is not reversed Click on the valve or pump you wish to test then click on the Send button to actuate the component Component activation status appears in the status box field Use the Close button to close this screen Actuate Outputs Select Actuate Outputs to display the Actuate Miscellaneous Output screen This screen provides a check of the ABS indicator lamp In addition it provides a way to check either inlet or outlet activity of the valves pump or retarder relay Click on the component you wish to test then click on the Send button to actuate the component Component activation status appears in the status box field Use the Close button to close this screen 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual T 5 1 1 1 Brakes Reset Memorized MAININ Select Reset Memorized to display the Learned Failure to bleed the system whenever any Component screen hydraulic system fitting is loosened or dis connected will allow air to remain in the sys Relay is an automatic default and cannot be de tem This will prevent the hydraulic pressure selected It indicates the ECU has memorized the in the brake system from rising enough to installed retarder relay Once the ECU has seen a Ine Nra tes COACH TAS WII caniae Mo
161. tions to clean ground or pol ished parts Damage to parts will result Use safety solvent or equivalent to clean the surfaces of ground or polished parts For rough metal parts Use a cleaning solvent or weak alkaline solution in a hot solution tank to clean rough metal parts If a hot solution tank is used follow the instructions below 1 Place the rough parts in the hot solution tank WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 2 Leave the rough parts in the tank until they completely cleaned and heated 3 Remove the rough parts from the tank 4 Thoroughly wash the rough parts with water until the alkaline solution is completely washed off of the parts DRY AND INSPECT PARTS 1 Use soft clean paper or cloth rags or compressed air to completely dry parts immediately after cleaning them 2 Carefully inspect each part for wear or damage 3 Repair or replace worn or damaged parts Caliper Piston Installation Brembo 68mm Caliper 1 Install the seals and dust boots in the caliper Refer to Seal and Dust Boot Replacement Brembo 68mm Caliper CAUTION While pressing the pistons back into their bores be careful to not damage the seal and the dust boots The dust boots must not be twisted or allowed to trap air If air becomes trapped in the dust cover use a flat blade to gently lift the edge of the
162. to Step 5 Testing and Wiring Repairs Did you find and correct the condition 3 1 Turn the ignition OFF Go to Step 4 Go to Step 6 2 Disconnect the powertrain control module PCM connector C2 3 Turn the ignition ON with the engine OFF 4 Measure the voltage from the vehicle speed signal circuit of the PCM to a good ground Does the voltage measure greater than the specified value WCC WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual T 1 26 DTC P0608 Step Action Valu s Replace the PCM Refer to Control Module References for replacement Go to Step 8 setup and programming Did you complete the replacement 1 Use the scan tool in order to clear the DTCs Go to Step 2 System OK 2 Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text Does the DTC reset WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis Service Manual m 5 1 27 Brakes DTC P0609 Conditions for Clearing the DTC Repair the condition responsible for setting the DTC Use a scan tool in order to clear the DTC The powertrain control module PCM converts the data After the DTC is cleared and the ignition is ON the ABS Circuit Description from the vehicle speed sensor to a 128k pulses mile indicator may remain ON until the EBCM completes a signal The electronic brak
163. tom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION m 9 7 Grease the cap or cover if equipped Coat the inside of the cap with wheel grease but do not fill the cap 8 Install the brake caliper Refer to Brake Caliper Replacement Bosch ZOH T Caliper NOTICE Workhorse does not recommend wheel stud replace ment every time a rotor is replaced unless the wheel stud is damaged or out of round when verified with a dial indicator If it is determined that any stud s need replacing they can be pressed out if access to a press is available to minimize any potential for stud rotor damage lf a press is un available the studs can be carefully driven out by using a brass mallet Be sure to wear proper eye hand protection and administer all safety precautions when performing either procedure Refinishing Brake Rotors You do not need to refinish brake rotors when doing routine brake maintenance such as replacing worn brake pad assemblies Refinish brake rotors only under the following circumstances There is a complaint of brake pulsation There is scoring greater than 1 5 mm 0 060 in Brake rotors have a minimum thickness dimension cast into them This dimension is the minimum wear dimension and not a refinish dimension Do not use a rotor that will not after refinishing meet the specifications shown on the brake rotor Always replace the rotor with a new rotor I
164. uid pressure for the system A pressure relief valve in the port block limits system pressure to around 1700 psi Proportional Solenoid Valve The proportional solenoid valve controls when fluid can return to the pump reservoir When the parking brake is released the valve is closed to hold pressure in the system When the parking brake is applied the valve opens to allow fluid to return to the pump reservoir If the vehicle is at a speed greater than five miles per hour Smph and the pull button is pulled the valve will remain open for a few moments and then release the pressure slowly for a gradual apply of the brake 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual SECTION 5 W Series Chassis SUPPLY GROUND VOLTAGE Brakes SOLENOID COIL PRESSURE TRANSDUCER ECM PIN ASSIGNMENTS 1 POWER IN PIN 2 PUMP RELAY GROUND 3 AUTO PARK WARNING LAMP POWER PIM 4 PARK BRAKE SWITCH INPUT 3 LEVELING JACKS INPUT amp OPENPUMP DER PUMP MOTOR PIN 8 OPEN 3 BUZZER INPUT e 10 MOTOR POWER INPUT PIM 11 SPEED SIGNAL INPUT PIN 12 PNP INPUT PIN 13 PARR BRAKE WARNING LIGHT CONTROL LEE Lc Figure 5 33 J72 Electrical Circuits WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION
165. ulfide It should have excellent anti corrosion and pull the sensor to remove it from the sensor bracket adhesion characteristics and be capable of continuous Do not pull on the cable function in a temperature range of 40 to 300 F 40 to 150 C NOTICE When replacing a Meritor WABCO ABS sensor you MUST also replace the spring clip and lubricate the bore of the sensor bushing or mounting block WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series Service Manual WORKHORSE CUSTOM CHASSIS SECTION W Series Chassis 9 dE Brakes 5 With the tabs on the inboard side push the sensor spring clip into the bushing in the steering knuckle until the clip stops 6 Push the sensor completely into the sensor spring clip until it contacts the tooth wheel 7 Fasten the sensor cable with tie wraps every 12 inches Properly bundle and store excess cable in the subframe 8 Remove the blocks and safety stands 9 Perform a voltage output check to ensure proper installation Refer to Sensor Output Voltage Test in this section Wheel Speed Sensor Replacement Rear Axle Removal 1 Apply the parking brake Chock the front tires to prevent vehicle movement 2 Raise the rear tires off of the ground Put safety stands under the axle 3 If the rear tire must be removed to gain access to the sensor release the parking brake to release the brake Figure 5 46 Typical Front WSS Installat
166. unting bracket to steering 427 Ib ft 172 N m Cua em Bolt Plug Bosch ZOH T 16 27 b ft 22 37 knuckle bolts Brembo 52mm Caliper Banjo bolt Meritor Quadraulic Caliper 35lbft 47 159 lb ft 215 Nm Bleed screw Brembo 52mm Caliper 124 Ib in 14 N m Caliper mounting bracket to steering Bleed screw Brembo 68mm Caliper 177 Ib in 20 N m knuckle bolts Bosch ZOH T Caliper 206 Ib ft 280 Bleed screw Bosch ZOH T Caliper 150 Ib in 17 Caliper mounting bracket to steering Bleed screw Meritor Quadraulic Caliper 97 Ib in 11 N m knuckle bolts Meritor Quadraulic Caliper 225 Ib ft 305 Brake hose fitting Brembo 52mm Caliper 164Ibin 18 5 N m 5 8 inch 18 bolt Brake hose fitting Brembo 68mm Caliper 2121bin 24 N m Caliper mounting bracket to steering knuckle bolts Meritor Quadraulic Caliper 150 Ib ft 203 N m Brake hose fitting Bosch ZOH T Caliper 168 Ib in 19 N m 9 16 inch 18 bolt Brake hose fitting Meritor Quadraulic Caliper 350 Ib ft 475 N m Cross over tube nuts Meritor Quadraulic 124 Ib in JA kein p Caliper Brake hose hold down clamp bolt Bosch Lining rail Covers Meritor Quadraulic ZOH T Caliper LI ZEE Caliper 195 Ibin 22N m clamp bolt Meritor 44 N m Rotor to hub bolts Brembo 52mm Caliper 140 Ib ft 190 N m Bak draai ing bolt Merit Rotor to hub bolts Brembo 68mm Caliper 130 Ib ft 176 N m rake pad retainer spring bo eritor 30 Ib ft 41 Rotor to
167. wards the bracket 4 Carefully clean the guide seat with suitable material and products e g a wet rag 5 Reinsert the sliding guide in its seat 6 Insert and tighten a new caliper slide pin 17 to the required torque see Fig 22 Figure 22 Install a NEW caliper mounting bolt 7 If replacing pads on rear wheels with leaf spring suspension the caliper body must be repositioned on the bracket and both guides reinserted 8 Carefully clean the part 18 to ensure a perfect seal and fit a new protective cap 19 see Fig 23 PAGE W Series Chassis 42 Brakes Figure 5 23 Install protective caps to bolt heads 0 Each time the pads are changed all the clamping screws and protective caps must be replaced 9 Push the brake pedal repeatedly to move the pistons against the disc until the pedal force and usual stroke are restored 10 Check the brake fluid level in the reservoir and top up if necessary 11 Close the brake fluid tank plug 12 Burnish the new brake pads before returning the vehicle to the customer WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS SECTION Service Manual 5 CAUTION When using new pads that have just been fit ted remember that braking will be less effec tive during the first brake applications You should therefore Reduce your speed Avoid sudden or prolonged braking Brake
168. y occur if the system malfunctions CAUTION Always protect the system from contamina tion by capping plugging or taping exposed lines and ports CAUTION Always secure or identify fastener hardware and brackets by tagging containing or tem porarily installing until the main component is to be installed WCC 2007 WorkhorseCustom Chassis All Rights Reserved W Series WORKHORSE CUSTOM CHASSIS Service Manual BRAKE ACTUATION LINKAGE BELL CRANK SERVICE A lubrication fitting has been added to the bell crank connecting the brake pedal to the master cylinder This fitting requires lubrication at each chassis service Vehicles without the lubrication fitting require the following steps to lubricate the bell crankshaft 1 Disconnect the linkage from the bell crank assembly 2 Remove the bolt retaining the bell crank shaft in the housing 3 Remove the shaft from the housing and inspect for damage or scoring If the shaft is damaged replace the bell crank assembly 4 Apply a liberal coat of chassis lube to the shaft and into the housing bore 5 Reinstall the shaft and replace the retaining bolt Lubricate the linkage pivot points before reconnecting 7 Check proper operation of the brake linkage to ensure free operation O SECTION 9 PAGE W Series Chassis 33 Brakes E ET we Figure 5 10 Bell crank lubrication point

2006 Section 5 - Brakes.indd - Oemys

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