Meritor 4 Piston Quadraulic Caliper
Contents
1. Y CROSSOVERTUBE 4006991a Figure 2 1 4 ArvinMeritor Maintenance Manual MM 2075 Revised 06 08 Hazard Alert Messages Read and observe all Warning and Caution hazard alert messages in this publication They provide information that can help prevent serious personal injury damage to components or both DANGER Before you perform any brake service identify the vehicle s hydraulic system and refer to the service manual for procedures Some brake application systems are fully pressurized and you cannot reduce this pressure by switching off the ignition or removing the battery To prevent death serious personal injury or damage to components you must carefully follow procedures for the hydraulic system you are servicing WARNING To prevent serious eye injury always wear safe eye protection when you perform vehicle maintenance or service Park the vehicle on a level surface Block the wheels to prevent the vehicle from moving Support the vehicle with safety stands Do not work under a vehicle supported only by jacks Jacks can slip and fall over Serious personal injury and damage to components can result ASBESTOS AND NON ASBESTOS FIBERS WARNING Some brake linings contain asbestos fibers a cancer and lung disease hazard Some brake linings contain non asbestos fibers whose long term effects to health are unknown You must use caution w2. Check the rotor while assembled to the hub or spoke wheel and mounted on the axle spindle The lateral runout of the rotor friction surfaces should not exceed 0 015 inch 0 381 mm total indicator reading TIR The thickness variation of the rotor should not exceed 0 001 2 inch 0 0300 mm e If the lateral runout or the thickness variation exceeds the above values Resurface or replace the rotor Caliper 1 Inspect the caliper before you reinstall it onto the torque plate The pistons should be fully retracted into the caliper Check to ensure the piston boots are not loose or damaged Verify the piston boots are fully seated into the housing If any leakage damage or defect is found it may be necessary to disassemble or replace the caliper Figure 5 6 40038018 2 Install the caliper over the rotor Install the washers and start the caliper to torque plate mounting bolts by hand 3 Depending on the caliper configuration tighten the four M20 mounting bolts or the six M14 mounting bolts Refer to Section 8 9 4 Install the brake hose Figure 5 7 4003802 Figure 5 7 5 secure the brake hose hold down clamp with the bolt Figure 5 8 BRAKE HOSE HOLD DOWN CLAMP BOLT 4003803a Figure 5 8 Brake Pads 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
3. for the diagnostic procedures Disassemble the caliper and replace the piston seals Replace the piston if it is damaged Check the rotor with a dial indicator Install a new rotor if the runout exceeds the maximum specified Adjust or replace the bearings as needed Drain and clean the system Replace with the recommended brake fluid Replace the hoses Check the runout with a dial indicator Install a new rotor if the runout exceeds the maximum specified Check the parallelism with a micrometer Resurface or install a new rotor as required Readjust the bearing to the specified torque Install the manufacturer recommended material Inspect for damage and install the pads with the friction material toward the rotor Conditions Brake Noise Scraping Brake Noise Groan Brake Noise Rattle Brake Noise Squeal Possible Causes Rust or mud build up on edges of rotor and on caliper housing Worn pad or pad installed backward Incorrect caliper alignment permitting rotor to scrape on housing Incorrect pad friction material Incorrectly installed brake pads backing plate facing the rotor Pressure on the brake pedal too light Incorrect pad friction material Incorrectly installed brake pads backing plate facing the rotor Excessive clearance between the shoe and caliper Pad retainer plate missing or not correctly positioned Incorrect pad friction material Incorrectly installed b
4. or a separate ABS ring attached to the rotor by bolts e 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 Operation The hydraulic caliper assembly consists of a caliper housing and four pistons The housing is bolted directly to the torque plate The torque plate is bolted to the axle flange or may be integrated with the axle The caliper receives hydraulic fluid pressure by way of the centrally located inlet port The inlet port can accept either a banjo bolt connection or an inverted flare type connection The arrows in Figure 2 1 show the fluid handling from the inlet port to each of the pistons Also shown is the fluid handling for bleeding air from the caliper Because there are two bleed screws a special bleeding sequence is required to remove all air from the system This procedure is detailed in Section 6 During a brake application the hydraulic pressure is uniformly applied to the rear of all pistons The pistons extend out of the bores and push the brake pads into contact with the rotor The hydraulic force creates a clamp force resulting in braking After the brake is released the pressure is released and the pistons retract ArvinMeritor Maintenance Manual MM 2075 Revised 06 08 3 2 introduction BLEEDER BLEEDER SCREW 4 S INLET
5. 2075 Revised 06 08 7 3 Disassembly 4 amp WARNING When you use compressed air to remove the pistons from the Caliper bore do not place your hands or fingers near the bore to catch or protect the pistons Serious personal injury can result 6 Install a plug screw in the inlet port on the inboard caliper half 7 Place a section of plate stock across the pistons to be removed Use a C clamp to hold the plate against the pistons on one side of the caliper where the pistons are to be removed Figure 3 8 4003787b Figure 3 8 CAUTION When you remove 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 8 Apply low air pressure no more than 25 psi 172 kPa with a rubber nosed air fitting to the crossover tube port Figure 3 9 Apply air supply to crossover tube port 4003794b Figure 3 9 ArvinMeritor Maintenance Manual MM 2075 Revised 06 08 4 amp WARNING Ensure the pistons are installed in the housing before you pressurize it to prevent serious personal injury and damage to components 9 Gradually open the C clamp to allow the pistons to move out evenly until free 10 Repeat the procedure for the other caliper half CAUTION Install a new caliper if the caliper bores are excessively scored or corroded Do not hone the caliper bore
6. any brake service You must adhere to the hydraulic application system bleeding procedures to prevent death serious personal injury or damage to components Refer to the manufacturer s service information for ABS bleeding instructions 1 Check the master cylinder reservoir and fill if necessary with DOT 3 or DOT 4 brake fluid ArvinMeritor Maintenance Manual MM 2075 Revised 06 08 2 Bleed the brakes in the following order right rear left rear right front and left front CAUTION When you bleed a four piston caliper monitor the brake fluid level to ensure you do not drain the system Add brake fluid to the reservoir as needed to prevent damage to components during operation Always install new brake fluid into the caliper Discard old brake fluid Do not reuse it Damage to components can result NOTE Each four piston caliper is equipped with two bleed screws To ensure air is removed from a caliper the bleed sequence is inboard outboard and repeat inboard 3 _ Install a section of clear flexible tubing with a 1 4 inch inner diameter over the inboard bleeder Insert the other end of the tubing into a container to collect the purged brake fluid Discard the brake fluid Do not reuse old brake fluid 4 pressurized bleeding system is not required by the vehicle manufacturer s service procedures apply and hold the brakes to pressurize the system Repeat the procedure for the outboard bleed screw Repeat
7. at all times during brake servicing beginning with the removal of the wheels Wear a respirator equipped with a high efficiency HEPA filter approved by NIOSH or MSHA if the exposure levels may exceed OSHA or manufacturers recommended maximum levels Even when exposures are expected to be within the maximum allowable levels wearing such a respirator at all times during brake servicing will help minimize exposure 3 Procedures for Servicing Brakes a Enclose the brake assembly within a negative pressure enclosure The enclosure should be equipped with a HEPA vacuum and worker arm sleeves With the enclosure in place use the HEPA vacuum to loosen and vacuum residue from the brake parts b Asan alternative procedure use a catch basin with water and a biodegradable non phosphate water based detergent to wash the brake drum or rotor and other brake parts The solution should be applied with low pressure to prevent dust from becoming airborne Allow the solution to flow between the brake drum and the brake support or the brake rotor and caliper The wheel hub and brake assembly components should be thoroughly wetted to suppress dust before the brake shoes or brake pads are removed Wipe the brake parts clean with a cloth c _ If an enclosed vacuum system or brake washing equipment is not available carefully clean the brake parts in the open air Wet the parts with a solution applied with a pump spray bottle that creates a fine mist Use a s
8. cannot remove stains and corrosion from the caliper bore Replace the caliper 3 Disassembly ArvinMeritor Maintenance Manual MM 2075 Revised 06 08 9 4 Prepare Parts for Caliper Assembly Hazard Alert Messages Read and observe all Warning and Caution hazard alert messages in this publication They provide information that can help prevent serious personal injury damage to components or both WARNING To prevent serious eye injury always wear safe eye protection when you perform vehicle maintenance or service Solvent cleaners can be flammable poisonous and cause burns Examples of solvent cleaners are carbon tetrachloride and emulsion type and petroleum base cleaners Read the manufacturer s instructions before using a solvent cleaner then carefully follow the instructions Also follow the procedures below e Wear safe eye protection e Wear clothing that protects your skin e Work in a well ventilated area e Do not use gasoline or solvents that contain gasoline Gasoline can explode e You must use hot solution tanks or alkaline solutions correctly Read the manufacturer s instructions before using hot solution tanks and alkaline solutions Then carefully follow the instructions Clean Dry and Inspect Parts Clean Parts For Ground or Polished Metal Parts CAUTION Do not use hot solution tanks or water and alkaline solutions to clean ground or polished parts Damage to parts can result Use a
9. the procedure for the inboard bleed screw Tighten the bleed screws to specification Refer to Section 8 ps T l Test the brakes prior to returning the vehicle to service Hazard Alert Messages Read and observe all Warning and Caution hazard alert messages in this publication They provide information that can help prevent serious personal injury damage to components or both WARNING To prevent serious eye injury always wear safe eye protection when you perform vehicle maintenance or service Brakes Conditions Excessive Pedal Effort Pedal Pulsation Brake Roughness or Chatter Vehicle Pulls to One Side Possible Causes Pads worn below minimum thickness Faded overheated condition glazed pads blued or heat checked rotors Grease oil or brake fluid on linings seized or frozen pistons Incorrect pad friction material Incorrectly installed brake pads backing plate facing the rotor Excessive lateral runout of brake rotor Excessive out of parallelism of brake rotor Loose or worn steering or suspension parts Excessive front bearing clearance Brake fluid oil or grease on linings Unmatched linings uneven lining wear distorted pads Rough rotor surfaces on one rotor seized or frozen pistons Loose caliper mounting bolts Uneven tire pressure tread wear or size right to left Excessive rotor parallelism or runout Restricted hose or line Front end out of alignment 7 Troubl
10. you perform vehicle maintenance or service Assembly 40037982 Brake Caliper When using compressed air use air lines that are completely free of oil and moisture All brake parts must be clean and completely dried of cleaning fluid Use only Meritor replacement parts to ensure correct caliper performance Figure 5 2 6 Pressthe pistons into the bores one at a time Use a block and C clamp to press the piston into the housing until lightly seated Repeat this procedure for the other pistons Figure 5 3 1 Assemble the crossover tube Tighten the crossover tube nuts Refer to Section 8 P 2 Ensure the parts are clean and free of debris Use compressed air to clean out and dry the grooves and passages 3 _ Dip new piston seals in new clean DOT hydraulic brake fluid and install into the piston seal groove in the caliper piston bores Verify that they are correctly seated 4 Apply a thin film of silicon grease or brake fluid to the caliper bore seal land between the piston boot and seal groove Apply the grease or brake fluid around the entire circumference of the caliper bore Figure 5 1 40037998 Figure 5 3 and press the ring side of the boots into the boot bore with a seal driver or other method to evenly install the boot An old bearing cup equal to the boot ring size helps install the boots Verify that the piston boot bead is seated back against the CALIPER shoulder of the projecting end of the piston Bo
11. 1 Remove the brake caliper and brake pads Refer to the 1 Check the rotor while assembled to the hub or spoke wheel procedures in this section and mounted on the axle spindle The lateral runout of the rotor 2 Drain all fluid from the caliper friction surfaces should not exceed 0 015 inch 0 381 mm total indicator reading TIR The thickness variation of the rotor should not exceed 0 0012 inch 0 0300 mm 4 Remove the piston boots by prying the metal ring portion of the boot out of the bore with a screwdriver Use care to avoid damage to the piston or bore Discard the boots Figure 3 7 3 Push all four pistons to the bottom of their bores e fthe lateral runout or the thickness variation exceeds the above values Resurface or replace the rotor e lf it is necessary to service the rotor hub hub seal or bearing Remove the caliper according to the procedure in this section 2 Remove the hub and rotor assembly according to the vehicle manufacturer s recommendation Torque Plate 1 Remove the caliper from the vehicle Refer to the procedure in this section 2 Remove the dust shield if installed from the torque plate 3 Remove the hub and rotor assembly according to the vehicle 4003796b manufacturer s recommended service procedure Figure 3 7 4 Remove the ABS sensor if equipped 5 Remove the torque plate to axle mounting bolts Figure 3 6 Remove the crossover tube ArvinMeritor Maintenance Manual MM
12. 12 LB FT 12 2 16 3 N m BRAKE HOSE HOLD DOWN BOLT 5 16 18 THREAD 9 12 LB FT 12 2 16 3 N m BLEEDER SCREWS 7 16 24 THREAD 17 22 LB FT 23 30 N m INLET PORT 7 16 24 THREAD BANJO BOLT 30 40 LB FT 40 8 54 4 N m INVERTED FLARE NUT 17 22 LB FT 23 30 N m CROSSOVER TUBE NUTS 7 16 24THREAD 10 17 LB FT 14 23 N m 4006998 Figure 8 1 ArvinMeritor Maintenance Manual MM 2075 Revised 06 08 DUST SHIELD BOLT 5 16 18 THREAD 9 12 LB FT 12 2 16 3 N m NV SSS S SE KR CALIPER TO TORQUE PLATE BOLTS 8 specifications BOLT ON ABS BRACKET AND DUST SHIELD CLIP Ms 14 THREAD 12 18 LB FT 16 3 24 5 N m TORQUE PLATE TO FLANGE BOLTS Refer to the vehicle manufacturer s torque specifications 6 BOLT MOUNT M14 THREAD Refer to the vehicle manufacturer s torque specifications 4 BOLT MOUNT M20 THREAD 320 360 LB FT 435 2 489 6 N m 4007012a Figure 8 2 Bridge Bolts WARNING Do not remove the bridge bolts to perform service procedures If the bridge bolts are removed they must be reinstalled correctly or serious personal injury brake loss or damage to components can result If the bridge bolts were removed install new bridge bolts and tighten them in the correct sequence according to the following procedure To obtain bolt hardware kits call ArvinMeritor s Commercial Vehicle Aftermarket at 888 725 9355 Do not rebuild the
13. Brake Caliper Bleeding Procedure Section 7 Troubleshooting Brakes Section 8 Specifications Torque Specifications 4X ASBESTOS FIBERS WARNING The following procedures for servicing brakes are recommended to reduce exposure to asbestos fiber dust a cancer and lung disease hazard Material Safety Data Sheets are available from ArvinMeritor Hazard Summary Because some brake linings contain asbestos workers who service brakes must understand the potential hazards of asbestos and precautions for reducing risks Exposure to airborne asbestos dust can cause serious and possibly fatal diseases including asbestosis a chronic lung disease and cancer principally lung cancer and mesothelioma a cancer of the lining of the chest or abdominal cavities Some studies show that the risk of lung cancer among persons who smoke and who are exposed to asbestos is much greater than the risk for non smokers Symptoms of these diseases may not become apparent for 15 20 or more years after the first exposure to asbestos Accordingly workers must use caution to avoid creating and breathing dust when servicing brakes Specific recommended work practices for reducing exposure to asbestos dust follow Consult your employer for more details Recommended Work Practices 1 Separate Work Areas Whenever feasible service brakes in a separate area away from other operations to reduce risks to unprotected persons OSHA has set a maximum allowable level of exp
14. IPER ASSEMBLY k A Sa J V a NNE ES i es a f 1 2 gt 4006997a The general assembly sequence is as follows 1 Assemble the dust shield to the torque plate The dust shield option varies by model 2 Assemble the torque plate to the axle flange 3 Assemble the hub and rotor assembly 4 Assemble the caliper over the rotor and bolt it to the torque plate 2 ArvinMeritor Maintenance Manual MM 2075 Revised 06 08 Features Four Piston Quadraulic Disc Brake Caliper Meritor Quadraulic disc brakes have four piston fixed mount caliper design for use on both front and rear drive axles An installation includes four major components the caliper assembly torque plate assembly optional dust shield hub or rotor assembly and attaching hardware There are two caliper to torque plate mounting styles for both the 64 mm and 70 mm size calipers One uses six M14 bolts and the other uses four M20 bolts Caliper Meritor caliper assemblies are designed as follows e The caliper assembly consists of two halves assembled with four bolts and washers e includes four hydraulic piston bores two brake pads two stainless steel lining wear plates installed with button head bolts a pad retainer spring and bolt bleed screw and crossover tube e he piston bores contain the pistons piston seals and piston boots e The crossover tubes connect the two halv
15. MERITOR an ArvinMeritor brand Maintenance Manual MM 20 5 Four Piston Quadraulic Disc Brake Caliper Revised 06 08 Az oervice Notes About This Manual This manual provides instructions for Meritor four piston Quadraulic disc brake calipers Before You Begin 1 Read and understand all instructions and procedures before you begin to service components 2 Read and observe all Warning and Caution hazard alert messages in this publication They provide information that can help prevent serious personal injury damage to components or both 3 Follow your company s maintenance and service installation and diagnostics guidelines 4 Use special tools when required to help avoid serious personal injury and damage to components Hazard Alert Messages and Torque symbols WARNING A Warning alerts you to an instruction or procedure that you must follow exactly to avoid serious personal injury and damage to components 4 amp CAUTION A Caution alerts you to an instruction or procedure that you must follow exactly to avoid damage to components This symbol alerts you to tighten fasteners to a specified torque value How to Obtain Additional Maintenance and Service Information On the Web Visit Literature on Demand at arvinmeritor com to access and order product service aftermarket and warranty literature for ArvinMeritor s truck trailer and specialty vehicle components ArvinMeritor Maintena
16. calipers with used caliper parts 1 Verify the two caliper halves are seated If necessary lightly press the halves together until correctly seated 2 Loosely assembly all bridge bolts 3 Perform the following two step bolt tightening procedure A Tighten the bolts to an initial torque of 50 Ib ft 68 Nem in the sequence 1 2 3 4 Figure 8 3 B Use torque angle equipment to turn the bolts 70 3 2 degrees in the sequence 1 2 3 4 4006999a Figure 8 3 ArvinMeritor Maintenance Manual MM 2075 Revised 06 08 8 Specifications Four Piston Quadraulic Disc Brake Components Description Specification Brake Pad Thickness Above Metal New 0 73 18 5 mm Minimum Thickness Above Metal Discard 0 125 3 2 mm Brake Fluid High Performance Brake Fluid DOT 3 or DOT 4 Per Manufacturer s Recommendation ArvinMeritor Maintenance Manual MM 2075 Revised 06 08 Meritor Heavy Vehicle Systems LLC 2135 West Maple Road Printed in USA Troy MI 48084 USA 800 535 5560 Copyright 2008 Revised 06 08 M t arvinmeritor com ArvinMeritor Inc Maintenance Manual MM 2075 16579 22882 VIN er
17. cleaning solvent or kerosene or diesel fuel to clean ground or polished metal parts or surfaces For Rough Metal Parts Use a cleaning solvent or a weak alkaline solution in a hot solution tank to clean rough metal parts If you use a hot solution tank follow the instructions below 1 Leave the rough parts in the tank until they are completely cleaned and heated ArvinMeritor Maintenance Manual MM 2075 Revised 06 08 2 Remove the rough parts from the tank 3 Wash the parts with water until you remove the alkaline solution Dry and Inspect Parts 1 _ Use soft clean paper or cloth rags or compressed air to completely dry parts immediately after you clean them 2 Carefully inspect all parts for wear or damage before you assemble them 3 Repair or replace worn or damaged parts Apply Corrosion Protection 1 Apply a thin layer of brake fluid to cleaned dried parts Be careful that you do not apply the fluid to the linings or rotor 2 Ifyou will store the parts apply a rust inhibitor that prevents corrosion and rust to all surfaces Store parts inside to prevent rust and corrosion 5 Assembly and Installation Hazard Alert Messages Read and observe all Warning and Caution hazard alert messages in this publication They provide information that can help prevent serious personal injury damage to components or both CALIPER WARNING To prevent serious eye injury always wear safe eye protection when
18. d Cylinder bore surface scored or corroded Caliper piston seal damaged or worn Caliper piston damaged Reservoir fluid level low Air in the caliper Air in the hydraulic application system Malfunction of the hydraulic application system Caliper piston seal damaged Excessive rotor runout or bent rotor Worn or excessively loose wheel bearings Low quality brake fluid Weak brake hose that expands under pressure Excessive lateral runout of rotor Lack of rotor parallelism Loose wheel bearing Incorrect pad friction material Incorrectly installed brake pads backing plate facing the rotor ArvinMeritor Maintenance Manual MM 2075 Revised 06 08 Correction Pressurize the caliper to determine the source of the leak If necessary replace the wheel seal Repair or replace the components or housing as necessary Repair or replace the components or housing as necessary Repair or replace the components or housing as necessary Disassemble the calipers clean the bore and replace the seals and boots Disassemble the calipers and install new seals and boots Replace the piston Check for causes of fluid leak repair as required and refill the reservoir Bleed the system as needed Bleed the caliper as needed Refer to the brake caliper bleed procedure Refer to the hydraulic application system manual for the correct bleeding procedure Refer to the hydraulic application system manual
19. disc brake calipers for leakage damage or defects to piston boots seals or pistons Replace or repair the parts as required 3 Clean and inspect the lining wear plates Replace damaged or worn wear plates 5 Assembly and Installation NOTE The inboard and outboard brake pads are identical except when they are equipped with a mechanical wear sensor 4 install the brake pads Install pads equipped with a mechanical wear sensor on the inboard side of the caliper Ensure that the friction surface is against the rotor Install the pad retainer spring and tighten the bolt Refer to Section 8 Figure 5 9 P BRAKE PAD RETAINER SPRING BOLT 40038048 Figure 5 9 5 Fill the master cylinder reservoir with new clean high performance DOT 3 brake fluid or equivalent Make several brake applications to move the brake pistons and linings out into contact with the brake rotors 6 Recheck the master cylinder reservoir and top off as necessary to the manufacturer s recommended level 4 amp CAUTION To remove air from the caliper you must use the two bleed screws in a specific sequence to correctly bleed the brakes Otherwise air can enter the system and affect brake performance Damage to components can result Bleed the brake system according to the vehicle manufacturer s procedure Bleed the caliper according to the procedure specified in Section 6 of this manual 8 Install the tire and wheel assembly according to th
20. e manufacturer s instructions 9 Lower the vehicle Road test for correct operation ArvinMeritor Maintenance Manual MM 2075 Revised 06 08 13 6 Inspection Hazard Alert Messages Read and observe all Warning and Caution hazard alert messages in this publication They provide information that can help prevent serious personal injury damage to components or both WARNING To prevent serious eye injury always wear safe eye protection when you perform vehicle maintenance or service Inspect Parts Caliper 1 Clean the area around the brake hose Use brake parts cleaner 2 Inspect the piston and boots for wear and damage Replace worn or damaged parts 3 Inspect the caliper lining wear plates for wear and damage Replace worn or damaged wear plates 4 Inspect the housing for cracks or damage Replace a cracked or damaged housing Torque Plate 1 Inspect the caliper mounting area of the torque plate for rust or corrosion Replace a damaged or worn torque plate 2 Use a wire brush to clean the caliper mounting area 3 Inspect the torque plate for cracks or elongated bolt holes e lf these conditions exist Replace the torque plate Brake Caliper Bleeding Procedure 4 amp DANGER This bleed sequence refers to bleeding the caliper and does not consider the hydraulic application system requirements Identify your vehicle hydraulic application system type and refer to that service manual before you perform
21. e manufacturer s recommended level 15 Install the tire and wheel assembly according to the manufacturer s instructions 16 Lower the vehicle Road test for correct operation Brake Caliper 1 Use a jack to raise the vehicle so that the wheels to be serviced are off the ground Support the vehicle with safety stands 2 Remove the tire and wheel assembly according to the manufacturer s instructions 3 Remove the brake hose hold down clamp bolt if equipped Figure 3 4 O BRAKE HOSE HOLD DOWN CLAMP BOLT BRAKE HOSE rig JE H Elio d p A i 4003 90a Figure 3 4 4 Remove the brake hose from the caliper Figure 3 4 4 amp WARNING Do not remove the bridge bolts to perform service procedures If the bridge bolts are removed you must reinstall them correctly to prevent serious personal injury and damage to components 5 Remove the caliper to torque plate assembly bolts Do not disassemble the bridge bolts joining the two halves of the caliper Refer to the bridge bolt procedure in Section 8 Figure 3 5 3 Disassembly BRIDGE BOLTS MOUNTING DO NOT REMOVE CALIPER TO TORQUE PLATE BOLTS BRIDGE BOLTS DO NOT REMOVE 4003791b 4003792a Figure 3 5 Figure 3 6 Rotor Disassembly NOTE Refer to the vehicle manufacturer s rotor specifications for Brake Caliper inspection and service requirements
22. es of the caliper piston to supply brake fluid to the outboard pistons How to Identify the Caliper The calipers are available in two sizes based on piston diameter 64 mm or 70 mm They are visually identifiable by boot color 64 mm is red 0 mm is black Check for an assembly number on the side of the caliper for specific handed part numbers Torque Plate The torque plate assembly may have a provision for an anti lock braking system ABS sensor using either a bolt on bracket press in bushing clearance hole or slot It also has provisions to mount an optional dust shield to protect the rotor and brake assembly from road contamination When the ABS system is not used or the sensor is mounted through the axle flange the supports are not equipped with the sensor bracket 2 introduction Hub and Rotor Meritor hub and rotor assemblies incorporate the following design features e The hub and rotor assemblies consist of a hub and rotor fitted with bearing cups and wheel attachment studs e There are two types of rotors used a U shaped rotor and a hat shaped rotor e Some rotors are equipped with a cast in ABS speed sensor tooth wheel typically with 100 slots Some rotors have separate ABS speed sensor tooth wheels attached to the rotor with bolts e Front hub and rotor assemblies can have various ABS speed sensor tooth wheels such as a separate ring mounted to the inboard end of the hub ABS teeth integral to the rotor
23. eshooting Correction Install new pads Replace the rotor and reface pads if sufficient lining remains Install new pads in the axle sets Disassemble the calipers and free pistons or replace the caliper Install the manufacturer recommended material Inspect for damage and install the pads with the friction material toward the rotor Check with a dial indicator Install a new rotor if the runout exceeds the maximum specified Check the parallelism or rotor thickness variation with a micrometer Resurface the rotor or install a new rotor if the parallelism exceeds the maximum allowed Replace the parts and realign Readjust the bearing to specifications Install new pads in the axle sets Install new pads in the axle sets Resurface or replace the rotor in the axle sets Disassemble the caliper and repair or replace Tighten to specifications Equalize to the recommended pressures Install the correct size tires with good tread Resurface or replace the rotor Examine the hoses and lines and replace as necessary Reset the alignment ArvinMeritor Maintenance Manual MM 2075 Revised 06 08 15 7 Troubleshooting Conditions Leaky Caliper No Braking Effect or Excessive Pedal Travel Brake Noise Chatter Possible Causes Wheel seal damaged A damaged wheel seal can make the wheel end and caliper appear as the problem Crossover tube damaged Bleeder screw damaged Inlet port damage
24. exposure to silica dust can cause silicosis a non cancerous lung disease Silicosis gradually reduces lung capacity and efficiency and can result in serious breathing difficulty Some scientists believe other types of non asbestos fibers when inhaled can cause similar diseases of the lung In addition silica dust and ceramic fiber dust are known to the State of California to cause lung cancer U S and international agencies have also determined that dust from mineral wool ceramic fibers and silica are potential causes of cancer Accordingly workers must use caution to avoid creating and breathing dust when servicing brakes Specific recommended work practices for reducing exposure to non asbestos dust follow Consult your employer for more details Recommended Work Practices 1 Separate Work Areas Whenever feasible service brakes in a separate area away from other un to reduce risks to unprotected persons Respiratory Protection OSHA has set a maximum allowable level of exposure for silica of O 1 d as an 8 hour time weighted average Some manufacturers of non asbestos brake linings recommend that exposures to other ingredients found in non asbestos brake linings be kept below 1 0 f cc as an 8 hour time weighted average Scientists disagree however to what extent adherence to these maximum allowable exposure levels will eliminate the risk of disease that can result from inhaling non asbestos dust Therefore wear respiratory protection
25. hen you handle both asbestos and non asbestos materials Removal Brake Pads Visually inspect all brake pads Replace the pads when the remaining lining reaches 1 8 inch 3 1 5 mm thickness e f you replace the pads Replace all the disc brake pads at the same time to maintain original brake balance e f a complete vehicle pad replacement is not necessary desirable Replace the pads on both wheel ends on the same axle 3 Disassembly Replace the Brake Pads 4X CAUTION The brake pads must be installed when you apply the brakes If brake pads are not installed damage to the pistons can result 1 Wear safe eye protection 2 Parkthe vehicle on a level surface Block the wheels to prevent the vehicle from moving 3 Use a jack to raise the vehicle so that the wheels to be serviced are off the ground Support the vehicle with safety stands 4 Remove the wheel and tire assembly according to the manufacturer s recommendation 5 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 the pistons into the caliper 6 Remove the pad retainer spring bolt Figure 3 1 BRAKE PAD RETAINER SPRING BOLT 4003786b Figure 3 1 7 Insert flat screwdrivers under the brake pad edges Work the pads out evenly to avoid binding Figure 3 1 4 amp CAUTION Avoid placing direct pressure on a
26. nce Manual MM 2075 Revised 06 08 Literature on Demand DVD LODonDVD The LODonDVD contains product service and warranty information for ArvinMeritor components To order the DVD visit Literature on Demand at arvinmeritor com and specify TP 0742 How to Obtain Tools and Supplies Specified in This Manual Call ArvinMeritor s Commercial Vehicle Aftermarket at 888 25 9355 to obtain Meritor tools and supplies Information contained in this publication was in effect at the time the publication was approved for printing and is subject to change without notice or liability Meritor Heavy Vehicle Systems LLC reserves the right to revise the information presented or to discontinue the production of parts described at any time pg i 10 11 12 13 14 15 18 Contents Asbestos and Non Asbestos Fibers Section 1 Exploded Views Section 2 Introduction Features Four Piston Quadraulic Disc Brake Caliper Caliper Torque Plate Hub and Rotor Operation section 3 Disassembly Removal Brake Pads Replace the Brake Pads Brake Caliper Rotor Torque Plate Disassembly Brake Caliper Section 4 Prepare Parts for Caliper Assembly Clean Dry and Inspect Parts Clean Parts Dry and Inspect Parts Apply Corrosion Protection Section 5 Assembly and Installation Assembly Brake Caliper Installation Torque Plate Rotor Caliper Brake Pads Section 6 Inspection Inspect Parts Caliper Torque Plate
27. olution containing water and if available a biodegradable non phosphate water based detergent The wheel hub and brake assembly components should be thoroughly wetted to suppress dust before the brake shoes or brake pads are removed Wipe the brake parts clean with a cloth d Wear a respirator equipped with a HEPA filter approved by NIOSH or MSHA when grinding or machining brake linings In addition do such work in an area with a local exhaust ventilation system equipped with a HEPA filter e NEVER use compressed air by itself dry brushing or a vacuum not equipped with a HEPA filter when cleaning brake parts or assemblies NEVER use carcinogenic solvents flammable solvents or solvents that can damage brake components as wetting agents 4 Cleaning Work Areas Clean work areas with a vacuum equipped with a HEPA filter or by wet wiping NEVER use compressed air or dry sweeping to clean work areas When you empty vacuum cleaners and handle used rags wear a respirator equipped with a HEPA filter approved by NIOSH or MSHA to minimize exposure When you replace a HEPA filter wet the filter with a fine mist of water and dispose of the used filter with care 5 Worker Clean Up After servicing brakes wash your hands before you eat drink or smoke Shower after work Do not wear work clothes home Use a vacuum equipped with a HEPA filter to vacuum work clothes after they are worn Launder them separately Do not shake or use compressed air to
28. osure for asbestos of 0 1 f cc as an 8 hour time weighted average and 1 0 f cc averaged over a 30 minute period Scientists disagree however to what extent adherence to the maximum allowable exposure levels will eliminate the risk of disease that can result from inhaling asbestos dust OSHA requires that the following sign be posted at the entrance to areas where exposures exceed either of the maximum allowable levels DANGER ASBESTOS CANCER AND LUNG DISEASE HAZARD AUTHORIZED PERSONNEL ONLY RESPIRATORS AND PROTECTIVE CLOTHING ARE REQUIRED IN THIS AREA 2 Respiratory Protection Wear a respirator equipped with a high efficiency HEPA filter approved by NIOSH or MSHA for use with asbestos at all times when servicing brakes beginning with the removal of the wheels 3 Procedures for Servicing Brakes a Enclose the brake assembly within a negative pressure enclosure The enclosure should be equipped with a HEPA vacuum and worker arm sleeves With the enclosure in place use the HEPA vacuum to loosen and vacuum residue from the brake parts b Asan alternative procedure use a catch basin with water and a biodegradable non phosphate water based detergent to wash the brake drum or rotor and other brake parts The solution should be applied with low pressure to prevent dust from becoming airborne Allow the solution to flow between the brake drum and the brake support or the brake rotor and caliper The wheel hub and brake assembly components
29. ots for the SOME 4003797a 64 mm and 70 mm pistons are color coded The 64 mm boot is red and the 70 mm is black Figure 5 4 uu o x 7 install the piston boots over the projecting ends of the pistons Figure 5 1 5 Apply DOT hydraulic brake fluid to the outside of the caliper pistons and install them in the caliper bores with the piston steel cap facing out verifying that they are square to the bore Figure 5 2 ArvinMeritor Maintenance Manual MM 2075 Revised 06 08 11 5 Assembly and Installation 4003800a Figure 5 4 8 If required replace the two stainless steel wear rails by removing the button head bolts Installation Torque Plate 1 Install the torque plate mounting bolts Tighten the bolts to the specified torque Refer to Section 8 Figure 5 5 MOUNTING 40038058 Figure 5 5 2 lf equipped install the ABS sensor according to the vehicle manufacturer s recommended service procedure 3 Install the hub and rotor assembly according to the vehicle manufacturer s recommended service procedure 4 Install the dust shield if equipped 5 Install the caliper Refer to the procedure in this section 12 ArvinMeritor Maintenance Manual MM 2075 Revised 06 08 Rotor 1 Install the hub and rotor assembly according to the manufacturer s recommended service procedures Verify that the mating surfaces of the hub or spoke wheel and rotor are clean and free of rust build up 2
30. piston or damage to components can result 8 Compress the pistons on each side Use a piece of plate steel Stock over the pistons to uniformly distribute the load Figure 3 2 ArvinMeritor Maintenance Manual MM 2075 Revised 06 08 8 3 Disassembly 4003787 Figure 3 2 9 Inspect the rotor for scoring warping cracks bluing heat spots or other damage or defects and minimum thickness Repair or replace if necessary 10 Inspect the disc brake calipers for leakage damage or defects to piston boots seals or pistons Replace or repair the parts as required 11 Clean and inspect the lining wear plates Replace damaged or worn wear plates NOTE The inboard and outboard brake pads are identical except when they are equipped with a mechanical wear sensor 12 Install the brake pads Install pads equipped with a mechanical wear sensor on the inboard side of the caliper Ensure that the friction surface is against the rotor Install the pad retainer spring and tighten the bolt Refer to Section 8 Figure 3 3 BRAKE PAD RETAINER SPRING BOLT 4003804a Figure 3 3 6 ArvinMeritor Maintenance Manual MM 2075 Revised 06 08 13 Fill the master cylinder reservoir with new clean high performance DOT 3 brake fluid or equivalent Make several brake applications to move the brake pistons and linings out into contact with the brake rotors 14 Recheck the master cylinder reservoir and top off as necessary to th
31. rake pads backing plate facing the rotor Glazed pads Weak pad retainer spring Foreign material embedded in linings Incorrect pad friction material Incorrectly installed brake pads backing plate facing the rotor 7 Troubleshooting Correction Clean or replace as necessary Replace the pads in the axle sets only with the friction surface against the rotor Correct the alignment Install the manufacturer recommended material Inspect for damage and install the pads with the friction material toward the rotor olightly increase the pedal effort to eliminate the noise Install the manufacturer recommended material Inspect for damage and install the pads with the friction material toward the rotor Install new pads Install a new pad retainer spring or position it correctly Install the manufacturer recommended material Inspect for damage and install the pads with the friction material toward the rotor Resurface or replace the pads in the axle sets only Install a new pad retainer spring Replace the pads in the axle sets only Install the manufacturer recommended material Inspect for damage and install the pads with the friction material toward the rotor ArvinMeritor Maintenance Manual MM 2075 Revised 06 08 17 8 specifications Torque Specifications BRAKE PAD RETAINER SPRING BOLTS M10 16 THREAD 28 32 LB FT 38 1 43 5 N m LINING WEAR PLATE BOLT Ms 14THREAD 9
32. remove dust from work clothes 6 Waste Disposal Dispose of discarded linings used rags cloths and HEPA filters with care such as in sealed plastic bags Consult applicable EPA state and local regulations on waste disposal Regulatory Guidance References to OSHA NIOSH MSHA and EPA which are regulatory agencies in the United States are made to provide further guidance to employers and workers employed within the United States Employers and workers employed outside of the United States should consult the regulations that apply to them for further guidance ArvinMeritor Maintenance Manual MM 2075 Revised 06 08 i 1 Exploded Views SPRING id LINING ASSEMBLY 6 M14 BOLT MOUNTING 4 M20 BUTTON MOUNTING HEAD BOLT BOLT PISTON PISTON WEAR _ gt SE On AS SEAL DUST DUST PISTON PLATE xI 4 EFIA BOOT BOOT SEAL BRIDGE BOLTS K S K K r PS NO SERVICE a REQUIRED Cedar i CUZ PISTON F P P 177 SS HOUSING 4 M20 BOLT MOUNTING STYLE SHOWN 40037840 ArvinMeritor Maintenance Manual 2075 Revised 06 08 1 1 Exploded Views AXLE DUST MOUNTING Lu SHIELD FLANGE DUST SHIELD MOUNTING BOLT 2 P AAG C gt TORQUE ui HUB AND on ROTOR 9 CALIPER MOUNTING BOLTS AND WASHERS er p L 0 78 YA TORQUE PLATE MOUNTING BOLTS AND WASHERS J V CAL
33. s which can affect piston fit and operation Damage to components can result 11 Remove the piston seals with a non metallic device Discard the seals Do not nick scratch or scar the piston bores or seal grooves Do not hone the caliper bores e lf the caliper bores are excessively scored or corroded Install a new caliper CAUTION The outside diameter of the piston is the caliper s primary sealing surface and is manufactured to very close tolerances Replace a piston if the outside diameter is damaged Do not refinish or use abrasives including an emery cloth on the piston Damage to components can result 12 Inspect the outside diameter of the pistons for scoring nicks corrosion wear and damage e fany of these conditions exist Replace the pistons Do not refinish or use abrasives 13 Inspect the caliper bore for scoring nicks corrosion wear and damage e fany of these conditions exist Replace the caliper CAUTION Use a crocus cloth to remove minor stains and corrosion from the caliper bore Do not use abrasives including an emery cloth If you cannot remove minor stains and corrosion replace the caliper bore to avoid damage to components 14 Inspect the caliper bore for minor stains and corrosion e f any of these conditions exist Use a crocus cloth to remove stains or corrosion Clean the caliper bore after using a crocus cloth Do not use abrasives including an emery cloth e f you
34. sh your hands before you eat drink or smoke Shower after work Do not wear work clothes home Use a vacuum equipped with a HEPA filter to vacuum work clothes after they are worn Launder them separately Do not shake or use compressed air to remove dust from work clothes 6 Waste Disposal Dispose of discarded linings used rags cloths and HEPA filters with care such as in sealed plastic bags Consult applicable EPA state and local regulations on waste disposal Regulatory Guidance References to OSHA NIOSH MSHA and EPA which are regulatory agencies in the United States are made to provide further guidance to employers and workers employed within the United States Employers and workers employed outside of the United States should consult the regulations that apply to them for further guidance Asbestos and Non Asbestos Fibers NON ASBESTOS FIBERS WARNING The following procedures for servicing brakes are recommended to reduce exposure to non asbestos fiber dust a cancer and lung disease hazard Material Safety Data Sheets are available from ArvinMeritor Hazard Summary Most recently manufactured brake linings do not contain asbestos fibers These brake linings may contain one or more of a variety of ingredients including glass fibers mineral wool aramid fibers ceramic fibers and silica that can present health risks if inhaled Scientists disagree on the extent of the risks from exposure to these substances Nonetheless
35. should be thoroughly wetted to suppress dust before the brake shoes or brake pads are removed Wipe the brake parts clean with a cloth c If an enclosed vacuum system or brake washing equipment is not available employers may adopt their own written procedures for servicing brakes provided that the exposure levels associated with the employer s procedures do not exceed the levels associated with the enclosed vacuum system or brake washing equipment Consult OSHA regulations for more details d Wear a respirator equipped with a HEPA filter approved by NIOSH or MSHA for use with asbestos when grinding or machining brake linings In addition do such work in an area with a local exhaust ventilation system equipped with a HEPA filter e NEVER use compressed air by itself dry brushing or a vacuum not equipped with a HEPA filter when cleaning brake parts or assemblies NEVER use carcinogenic solvents flammable solvents or solvents that can damage brake components as wetting agents 4 Cleaning Work Areas Clean work areas with a vacuum equipped with a HEPA filter or by wet wiping NEVER use compressed air or dry sweeping to clean work areas When you empty vacuum cleaners and handle used rags wear a respirator equipped with a HEPA filter approved by NIOSH or MSHA for use with asbestos When you replace a HEPA filter wet the filter with a fine mist of water and dispose of the used filter with care 5 Worker Clean Up After servicing brakes wa
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