BENDIX BW1671 User's Manual
Contents
1. 11 controller is equipped with a retarder disable circuit which when coupled with an electrical relay will disable the vehicle retarder engine or transmission during an antilock stop The retarder disable function is not essential but is highly recommended for vehicles equipped with a retarder Connection to pin B on the EC 11 controller provides this function PIN C Pin C connects directly to negative vehicle ground PIN A dash light and its electrical relay are controlled by the EC 11 controller through pin D The light advises the driver of the antilock system condition PISTON PIN E The serial link allows the EC 11 controller to report its operating PIN IF condition to a specialized external computer in response to certain commands it receives The serial link configuration conforms to S A E standard J1708 Pins E and F provide serial link connections to the EC 11 controller but the function is not essential for MC 11 tractor antilock assembly operation PINL Sensors mounted at the wheel end send wheel speed information PIN M to the EC 11 controller through pins L M and N P The EC 11 controller receives the information at PIN N 100 pulses per wheel revolution The MC 11 tractor antilock assembly knows what s happening at the wheel ends because of the signals it receives from the wheel speed sensors The sensors are actually A C generators They create a magnetic field2. The red SNS LEDs illuminate AND LATCH ON to indicate any one of a number of permanent or intermittent failures For example open or shorted wheel speed sensor open or shorted sensor wiring no wheel speed signal CONT LED This red LED illuminates AND LATCHES ON if the EC 11 controller is malfunctioning or if excessive electrical spikes are present in the power line PWR LED This green LED illuminates and remains on during vehicle operation to indicate that vehicle power is reaching the EC 11 controller TROUBLESHOOTING GENERAL While the EC 11 controller diagnostic display locates a specific problem area it is still necessary to determine whether the problem resides in the component itself or the wiring Basically the troubleshooting procedure that follows is devoted to narrowing down the problem to either the wiring or a specific antilock component TIPS 1 10 All troubleshooting should begin by performing the STARTUP which focuses on observing the antilock status light on the dash The troubleshooting technician should record all findings and the action taken during the troubleshooting process No voltage or resistance tests are performed into the EC 11 controller All electrical tests begin at the wire harness end of the connector and move AWAY from the EC 11 controller toward and antilock system component modulator wheel speed sensor etc TROUBLESHOOTING INITIAL ST
3. Bendix 11 Tractor AntiLock 14 PIN CONNECTOR DELIVERY FIGURE 1 DESCRIPTION The Bendix MC 11 tractor antilock assembly is designed to improve vehicle stability by reducing wheel lock up during aggressive braking Like the MC 10 antilock assembly that it replaces the MC 11 tractor antilock assembly is a one channel system it uses one modulator And the system can control single or tandem axles The antilock assembly mounts to the vehicle frame and usually replaces the drive axle service relay valve The MC 11 tractor antilock assembly consists of an EC 11 electronic controller and an M 12 modulator The EC 11 controller houses the electronics that regulate the antilock system The electronics are protected by a self healing silicone compound The EC 11 controller contains a diagnostic window and reset switch and its 14 pin connector is the electrical link to the rest of the antilock system See Figure 2 The controller mounts to the modulator with four cap screws and itis electrically connected to the modulator 11 LED DIAGNOSTIC CONTROLLER DISPLAY 1 MODULATOR DELIVERY with a four pin connector The M 12 modulator has two components solenoids which rapidly apply and exhaust air during an antilock stop and a standard relay valve See SD 13 4772 for more information on the M 12 modulator The air connections for the MC 11 tractor antilock assembly are as fol
4. controller diagnostic window allows the driver to be aware of any problems that occur but not to be confused by diagnostic information A special feature of the MC 11 antilock system is failure latching When the controller senses an error it stores the condition in memory disables antilock and illuminates the dash light and the appropriate LEDs on the EC 11 controller The condition is truly stored it is not cleared by loss of power to the EC 11 controller The LEDs will re light when power is restored and will remain illuminated until the problem is corrected After the actual problem is discovered and corrected maintenance personnel can clear the EC 11 controller diagnostics by passing a small magnet over the RESET area in the window DIAGNOSTIC LEDs There are six LEDs and a magnetic reset switch on the EC 11 controller diagnostic window VOLT LED This red LED illuminates when power to the EC 11 controller falls outside the acceptable range of 9 18 volts If the voltage returns to within the acceptable range the VOLT LED will go off This is the only LED that will reset itself when the failure condition no longer exists MOD LED This red LED illuminates AND LATCHES ON when solenoid resistance is not within the acceptable range of 9 5 11 5 ohms It can also illuminate if excessive electrical spikes are present in the power line SNS 1 AND SNS 2
5. the modulator turn the vehicle ignition key to the ON position One short burst of air should be noted from the modulator exhaust If one short burst of air is not noted or if the exhaust is prolonged and not short sharp and well defined refer to the troubleshooting section WARNING PLEASE READ AND FOLLOW THESE INSTRUCTIONS TO AVOID PERSONAL INJURY OR DEATH When working on or around a vehicle the following general precautions should be observed at all times 1 Park the vehicle on a level surface apply the parking brakes and always block the wheels Always wear safety glasses Stop the engine and remove ignition key when working under or around the vehicle When working in the engine compartment the engine should be shut off and the ignition key should be removed Where circumstances require that the engine be in operation EXTREME CAUTION should be used to prevent personal injury resulting from contact with moving rotating leaking heated or electrically charged components Do not attempt to install remove disassemble or assemble a component until you have read and thoroughly understand the recommended procedures Use only the proper tools and observe all precautions pertaining to use of those tools 10 If the work is being performed on vehicle s air brake system or any auxiliary pressurized air systems make certain to drain the air pressure from all reservoirs before beginning ANY work on the
6. and when the field is interrupted by an irregular surface like a tone ring A C voltage is produced The frequency of voltage increases or decreases as wheel speed increases or decreases During normal non antilock operation the M 12 modulator inlet solenoid is open and the exhaust solenoid is closed In this condition the M 12 modulator is a regular R 12 relay valve It receives a control signal from the foot valve 3 EXHAUST SOLENOID 0000000000100000000 INLET SOLENOID DOUBLE CHECK VALVE TRAILER CONTROL BRAKE VALVE VALVE CONTROL RESERVOIR DELIVERY EXHAUST FIGURE 4 BALANCED POSITION which passes through the open inlet solenoid and into the control cavity of the relay valve The valve then applies air to the service brake chambers in proportion to the control signal If wheel lock is impending the EC 11 electronic controller commands the solenoids to modulate brake chamber pressure on the axles in which the system is installed OPERATION APPLYING Normal Service Application When a normal service brake application is made control air pressure from the brake valve enters the modulator control port The air passes through the supply solenoid and acts on the modulator s piston The piston closes the modulator exhaust and opens the inlet delivering supply air out the delivery ports BALANCED POSITION Normal Service Application The modulator
7. its hex screw and pulling the connector away from its socket 4 Remove and save the mounting hardware connecting the MC 11 assembly to the vehicle INSTALLATION OF THE 11 ASSEMBLY 1 Replace the 11 assembly on the vehicle using the hardware saved during removal Connect the air lines to the proper ports as identified during removal Connect the 14 pin connector into the controller and tighten the hex screw 2 Perform OPERATIONAL AND LEAKAGE TESTS before placing vehicle back into service DISASSEMBLY The following disassembly and assembly procedure is presented for reference purposes and presupposes that a major rebuild of the antilock valve is being undertaken Several replacement parts and maintenance kits are available which do not require full disassembly The instructions provided with these parts and kits should be followed in lieu of the instructions presented here Refer to Figure 7 throughout the procedure CAUTION The MC 11 assembly may be lightly clamped in a bench vise during disassembly However overclamping will result in damage leakage and or malfunction If a vise is to be used position the MC 11 assembly so the jaws bear on the flat area of the supply port and its opposing side of the body 1 Remove the EC 11 controller 1 from the M 12 modulator by removing the controller s four mounting bolts 2 Lift the controller off the M 12 modulator and detach the wire harn
8. permitted DELIVERY le 5 Ifleakage is excessive around the supply and exhaust solenoids replace the M 12 modulator OPERATIONAL TEST LED Operation Although the MC 11 assembly has self check diagnostics the LEDs Light Emitting Diodes should be inspected to ensure that they are functioning properly With the vehicle ignition on hold a magnet capable of picking up 3 ounces to the RESET position on the diagnostic window All LEDs should illuminate If one or more of the LEDs do not illuminate and the dash light indicates proper system function note the nonilluminated LEDs for future reference Diagnostic capabilities will be limited but the system will continue to function as designed Solenoid Operation The MC 11 assembly monitors the system electronics upon vehicle start up However the vehicle should be tested to verify proper solenoid function Two technicians will be required to properly test the solenoids 1 Parkthe vehicle on a level surface and block the wheels Release the parking brakes and build the air system to full pressure 2 Turn the engine ignition key to the OFF position Then make and hold a full brake application EXHAUST SOLENOID INLET SOLENOID DOUBLE CHECKVALVE TRAILER CONTROL VALVE BRAKE VALVE CONTROL PISTON DELIVERY FIGURE 6 ANTILOCK MODE SOLENOIDS ACTIVATED 3 With the brake application held and a technician near
9. reaches a balanced position when control pressure acting upon the topside of the piston approaches that of the air acting upon the underside of the piston The piston moves upward and closes the inlet valve while the exhaust remains closed This prevents the modulator from delivering or exhausting air EXHAUSTING Normal Service Application When the brake valve is released control pressure exhausts through the supply solenoid and the check valve in the 4 solenoid housing and out the exhaust port ofthe brake valve As the piston moves upward the modulator s exhaust opens allowing air from the piston s underside to exhaust through the modulator exhaust port ANTILOCK MODE Solenoids Activated If a service brake application is made and the EC 11 controller senses impending wheel lockup it will command the antilock system to alter the service brake application automatically When activated shuttles within the solenoids alter the application and exhaust of control air pressure The supply solenoid closes preventing control line pressure from entering the modulator Then the exhaust solenoid opens allowing control pressure to exhaust from the top side of the piston through the exhaust port of the solenoid assembly This activity occurs in a pulsating manner simulating pumping of the brakes PREVENTIVE MAINTENANCE GENERAL Perform the inspections and tests at the prescribed intervals If the MC 11 tractor antil
10. vehicle If the vehicle is equipped with AD IS air dryer system or a dryer reservoir module be sure to drain the purge reservoir Following the vehicle manufacturer s recommended procedures deactivate the electrical system in a manner that safely removes all electrical power from the vehicle Never exceed manufacturers recommended pressures Never connect or disconnect a hose or line containing pressure it may whip Never remove a component or plug unless you are certain all system pressure has been depleted Use only genuine Bendix replacement parts components and kits Replacement hardware tubing hose fittings etc must be of equivalent size type and strength as original equipment and be designed specifically for such applications and systems Components with stripped threads or damaged parts should be replaced rather than repaired Do not attempt repairs requiring machining or welding unless specifically stated and approved by the vehicle and component manufacturer Prior to returning the vehicle to service make certain all components and systems are restored to their proper operating condition REMOVAL OF THE 11 ASSEMBLY 1 Prior to disassembly remove as much contamination as possible from the exterior of the assembly Be sure to keep the contamination away from the open ports 2 Remove and identify all air lines connected to the unit 3 Disconnect the 14 pin connector from the unit by unscrewing
11. ART UP PROCEDURE TURN VEHICLE IGNITION ON OBSERVE AMBER DASH LIGHT DASH LAMP DOES NOT BLINK IT COMES ON AND REMAINS ON DASH LIGHT NOTON GO TO SECTION II INSPECTION FOR ILLUMINATED LED S ACCELERATE VEHICLE ABOVE 10 MPH FOR AT LEAST 30 SECONDS GO TO SEC TION I DASH LIGHT TEST 55555 RRA t I 5255090 LI 55555 BOSSY 6555509 555564 552220502 KS J DASH LIGHT STAYS ON DASH LIGHT GOES OFF GO TO SECTION II INSPECTION FOR ILLUMINATED LED S SYSTEM IS FUNCTIONING PROPERLY 11 TROUBLESHOOTING SECTION I DASH LIGHT TESTING DISCONNECT 14 PIN CONNECTOR FROM EC 11 CONTROLLER OBSERVE DASH LIGHT DASH LIGHT OFF WITH IGNITION ON MEASURE VOLTAGE BETWEEN DASH LIGHT RELAY PIN D AND GROUND PIN C VOLTAGE SHOULD BE SAME AS BATTERY VOLTAGE o gt 2552 250 I OJ 590609042 05 K gt CRA KA X 5950 KI 5 25 05 lt 5 50 J lt lt lt 5 6 R Ke N Li REPLACE 11 CONTRO R CHECK WIRING HARNESS AND RELAY FOR SHORTS TO GROUND RECONNECT AND CHECK REPLACE THE FOLLOWING 1 DASH LIGHT BULB 2 FUSE 3 RELAY POWER WIRE 4 RELAY AFTER REPLACING A COMPONENT TEST THE DASH LIGHT 12 TROUBLESHO
12. BLY CHECK RESISTANCE ACROSS BOTH PAIRS OF WIRES WHITE WHITE BLACK BLACK RESISTANCE OUTSIDE 9 5 11 5 OHMS REPLACE M 12 MODULATOR NO CONTINUITY x Z gt SNS1 225 SNS2 _ CONT i PWR 16 REPEAT STARTUP RECORD INDICATED FAILURE PERFORM MOD MOD LED GOES OFF INTERMITTENT CONNECTION BETWEEN EC 11 CONTROLLER AND 12 MODULATOR CHECK 4 PIN CONNECTOR REPEAT STARTUP TROUBLESHOOTING SECTION VI PART A TESTING WHEEL SPEED SENSOR RECORD INDICATED RESET MAGNET HERE FAILURE za TO RESET VOLT IMOD _ SNS1 1 5 5 52 PERFORMARESET ANY SNS LEDS ON CONT 5 PWR STILL ON CHECK FOR PRESENCE OF TONE RING OR MISSING TONERING TEETH OPEN CONNECTOR FOREACH SENSOR AND OBSERVE LEDS CHECK FOR OUT OF SPEC SENSOR GAP IF THE OTHER SNS LED IF THE OTHER SNS SHOULD BE 0 015 ILLUMINATES AGOOD LED DOES NOT SENSOR WAS ILLUMINATE THE DISCONNECTED PROBLEM SENSOR RECONNECT IT AND TEST WAS DISCONNECTED THE OTHER SENSOR CHECK FOR EXCESSIVE WHEEL BEARING FREE PLAY INSPECT FOR BROKEN OR CRIMPED WIRES LEADING TO THE PROBLEM SENSOR CLEAN CONTACTS AT THE SENSOR AND ITS CONNECTOR REPEAT STARTUP E IN 110002 MEASURE RESISTANCE AT SNS 2 THE PROPER PIN LOCATIONS ON THE 14 PIN CONN
13. D TONE RINGS NOT PRESENT OR INGOOD CONDITION DAMAGED CHECK FOR OUT OF SPEC REPAIR REPLACE AS NECESSARY SENSOR GAPS SHOULD BE 0 015 GAP OUT OF SPEC ADJUST AS NECESSARY REPEAT STARTUP IF TESTING RETURNS TO THIS PLACE TWICE REPLACE THE EC 11 CONTROLLER REPEAT STARTUP 19 TROUBLESHOOTING SECTION VII PART B TESTING FOR FALSE FAILURE CAUSED BY DASH LIGHT RELAY HOLD MAGNET HERE TO RESET _ ALL LEDS SHOULD BE ON 20 RESET i VOLT MOD SNS1 218782 CONT PWR NO CONTINUITY REPAIR REPLACE WIRE HARNESS RECONNECT 14 PINCONNECTOR AND REPEAT STARTUP CHECK DASH WIRING AND CONNECTORS CONSULT VEHICLE MANUAL FOR FURTHER TROUBLE SHOOTING INFORMATION REPAIR REPLACE AS NECESSARY AND REPEAT DASH LIGHT OFF REPEAT STARTUP IF TESTING RETURNS TO THIS PLACE TWICE REPLACE THE 11 CONTROLLER BW1671 2004 Bendix Commercial Vehicle Systems LLC All rights reserved 4 2004 Printed in U S A REMOVE MAGNET TURN IGNITION OFF CHECK FOR CONTINUITY BETWEEN PIN D AND ITS TERMINAL ON THE DASH LIGHT RELAY NO POWER HOLD A MAGNET TO THE RESET SWITCH AND MAKE SURE ALL LEDS ILLUMINATE WHEN MAGNET IS PRESENT LEDS ILLUMINATED CONTINUITY CHECKFOR POWER HERE FROM PIND RECONNECT 14 PIN CONNECTOR TURN IGNITION ON AND CHECK REMOVE MAGNET CONTROLLER REPEAT STARTUP ps
14. ECTOR SNS 1 PINS N AND P SNS 2 PINS L AND M SNS 1 GO TO SECTION VI PART B 17 TROUBLESHOOTING SECTION VI PART B TESTING THE MODULATOR START HERE RESISTANCE WITHIN 1500 2500 OHMS RESISTANCE OUTSIDE 1500 2500 OHMS DISCONNECT SENSOR FROM WIRE HARNESS MEASURE RESISTANCE ACROSS SENSOR PINS RESISTANCE SHOULD BE 1500 2500 OHMS REPLACE EC 11 CONTROLLER REPEAT STARTUP CHECK WIRING THAT REPLACE SENSOR LEADS TO SENSOR FOR INTERMITTENT CONNECTIONS AND En 22 STARTUP NECESSARY REPEAT STARTUP 18 TROUBLESHOOTING SECTION VII FALSE FAILURE INDICATION NOTE IF DURING STARTUP THE DASH LIGHT ILLUMINATED WITHOUT BLINKING GO TO SECTION VII PART B TESTING FOR FALSE FAILURE CAUSED BY DASH LIGHT RELAY F THE DASH LIGHT BLINKED DURING STARTUP BUT ILLUMINATED AFTER THE VEHICLE REACHED 10 GO TO SECTION VII PART A TESTING FOR FALSE FAILURE CAUSED BY WHEEL SPEED COMPONENTS HOLD MAGNET HERE TO RESET n HOLD A MAGNET TO THE RESET SWITCH AND MAKE SURE ALL LEDS ILLUMINATE WHEN MAGNET IS PRESENT VOLT ALLLEDS MOD SHOULD LEDS ILLUMINATED BE ON CONT _ PWR REMOVE MAGNET REMOVE MAGNET BOTH SENSORS MAY NOT BE RECEIVING ONTROLLER SIGNALS REPEAT STARTUP CHECK FOR PRESENCE OF TONE RINGS TONE RINGS PRESENT AN
15. ESHOOTING SECTION IV INSPECTION FOR ILLUMINATED LEDS IS THE GREEN PWR LED ON MAGNET HERETO YES NO RESET PINA POWER RECORD INDICATED RED TURN IGNITION OFF DISCONNECT LED FAILURE VOLT AND EC 11 CONTROLLER OR CONT 14 PIN CONNECTOR A RESET ale TURN IGNITION ON cia ARESET MEASURE VOLTAGE BETWEEN PINS A AND C ON THE 14 PIN CONNECTOR 2 SNS1 SNS2 TAr AGI IL 10000 Ol CONT PWR LED S OFF LED S OFF VOLTAGE VOLTAGE BETWEEN 9 18 OUTSIDE 9 18 VOLTS VOLT RANGE MAY HAVE AN INTERMITTENT FAILURE CHECK VEHICLE ELECTRICAL SPIKES OR TRANSIENT VOLTAGE RECONNECT 14 PIN CONNECTOR CHECK VEHICLE WIRING REFER TO VEHICLE SERVICE MANUAL AND CHECK BATTERY REPAIR CONTROLLER REPEAT STARTUP 15 MAGNET ai TO RESET RESISTANCE WITHIN 9 5 11 5 OHMS CHECKFOR SHORT BLACK TO CASE GROUND AND WHITE TO CASE GROUND CONTINUITY REPLACE M 12 MODULATOR SECTION V TESTING MODULATOR TROUBLESHOOTING RESET SNS1 i SNS2 C gt CONT PWR REPLACE EC 11 CONTROLLER ARESET MOD LED STAYS ON STILL ON DISCONNECT THE 4 PIN CONNECTOR BETWEEN THE 11 CONTROLLER AND THE 12 MODULATOR SOLENOID ASSEM
16. OTING SECTION Il INSPECTION FOR ILLUMINATED LEDS INSPECT 11 CONTROLLER FOR ILLUMINATED LED S CHECK FOR GREEN PWR ON GREEN PWR GREEN PWR LED ON LED OFF VOLT ARE ANY RED ARE gt ARE ANY RED MOD LEDS ON ANY LEDS ON ON 8 52 CONT O PWR NOTE ILLUMINATED GO TO SECTION LED S AND GO TO VII FALSE FAIL SECTION IIl URE INDICATION INSPECTION FOR ILLUMINATED RED LED S REPLACE EC 11 GOTO SECTION IV CONTROLLER TESTING FORPOWERTO AND REPEAT EC 11 CONTROLLER STARTUP 13 TROUBLESHOOTING SECTION III INSPECTION FOR ILLUMINATED RED LEDS INSPECT 15 CONTROLLER FOR PRESENCE OF ILLUMINATED LEDS AND RECORD RESET MOLT MOD C SNS1 3 SNS2 CONT PWR RED CONTROLLER LED CONT IS ILLUMINATED RED MODULATOR LED MOD IS ILLUMINATED RED VOLTAGE LED VOLT IS ILLUMINATED RED SENSOR LED SNS IS ILLUMINATED GO TO SECTIONV TESTING MODULATOR GO TO SECTION IV TESTING FOR POWER TO EC 11 CONTROLLER GO TO SECTION VI TESTING WHEEL SPEED SENSOR VOLTAGE LED ILLU MINATES WHEN POWER TO 11 CONTROLLER FALLS OUTSIDE 9 18 VOLT RANGE IF VOLTAGE RETURNS TO AN ACCEPTABLE LEVEL THE LED WILL GO OFF GO TO SECTION IV TESTING FOR POWER TO EC 11 CONTROLLER 14 TROUBL
17. a FOR POWERAT THE DASH LIGHT RELAY COIL CONNECT OPPOSITE END OF RELAY COILTO GROUND AND NOTE REACTION OF DASH LIGHT DASH LIGHT ON REPLACE RELAY REPEAT STARTUP RELAY RELAY IF LIGHT IS ON BAD RELAY
18. ess from the base of the controller To detach the harness depress the tab on the side of the 4 pin connector and pull the connector from its socket in the controller Remove the gasket 7 from the recess in the EC 11 controller body NOTE If replacement of the controller only is required proceed to Step 8 of assembly 3 Remove the four 1 2 bolts that secure the solenoid assembly 2 to the valve body 3 Separate the solenoid assembly and valve body 4 Remove sealing ring 4 from the protrusion on the bottom of the solenoid assembly 5 Using a pair of snap ring pliers remove retaining ring 14 Remove the exhaust assembly 13 Remove o ring 12 o ring 11 from the 1 0 and O D respectively of the exhaust assembly 6 Remove spring 10 Remove the inlet exhaust assembly 8 Remove the spring seat 9 from the inlet exhaust assembly 7 Using your thumb press the piston stem and push the piston 6 out the opposite end of the body Remove o ring 5 from the piston 8 Discard all items that have replacement parts in the maintenance kit CLEANING AND INSPECTION 1 Using mineral spirits or an equivalent solvent clean and thoroughly dry all parts to be reused Do not allow mineral spirits to come into contact with the ECU connector or solenoids 2 Inspect the interior and exterior of all parts that will be reused for severe corrosion pitting and cracks Superficial corrosion and or pitting on the exterior por
19. lows AIR CONNECTION EMBOSSED IDENTIFICATION Supply to reservoir SUP Delivery to brake actuator DEL Control to rear service brake valve delivery CON 14 PIN CONNECTOR CALLOUTS PIN CONNECTION POWER RETARDER DISABLE lt GROUND DASH LIGHT SERIAL LINK SERIAL LINK UNUSED UNUSED UNUSED UNUSED SENSOR SENSOR SENSOR SENSOR u lt 2 O O gt 14 PIN CONNECTOR EXH BLK PWR EXH BLK GRD EXH WHT PWR EXH WHT GRD GROUND POWER SENSOR se R RETARDER SERIAL LINK SENSOR CONNECTOR FIGURE 2 TYPICAL MC 11 TRACTOR ANTILOCK WIRING SCHEMATIC EXHAUST SOLENOID LB m INLET SOLENOID DOUBLE CHECKVALVE TRAILER CONTROL VALVE BRAKE VALVE CONTROL E ca NV iI RESERVOIR EXHAUST FIGURE APPLYING NORMAL SERVICE APPLICATION The wiring connections on the 14 pin connector are as follows PIN A Power PIN IF Serial Link PIN B Retarder Disable PIN L Sensor PIN C Ground PIN M Sensor PIN D Dash Light PIN N Sensor PIN E Serial Link PIN P Sensor PINA Vehicle power is supplied to the EC 11 controller from the ignition switch through a fuse to pin Aon the 14 pin connector PIN 8 The
20. ock assembly fails to function as described repair or replace the unit EVERY 3 MONTHS 25 000 MILES 900 OPERATING HOURS OR DURING THE VEHICLE CHASSIS LUBRICATION INTERVAL EXHAUST SOLENOID INLET SOLENOID DOUBLE CHECK VALVE TRAILER CONTROL VALVE BRAKE VALVE CONTROL PISTON EXHAUST FIGURE 5 EXHAUSTING NORMAL SERVICE APPLICATION 1 Remove any accumulated contaminants and visually inspect the exterior of the unit for excessive corrosion or physical damage 2 Inspectall air lines and wiring connected to the MC 11 tractor antilock assembly for signs of wear or physical damage Replace as necessary 3 Perform LEAKAGE TEST EVERY YEAR 100 000 MILES OR 3 600 OPERATING HOURS 1 Perform OPERATIONAL AND LEAKAGE TESTS OPERATIONAL AND LEAKAGE TESTS LEAKAGE TEST 1 Park the vehicle on a level surface and block the wheels Release the parking brakes and build the air system to full pressure 2 Turn the engine OFF and make 4 or 5 brake applications Note that the service brakes apply and release promptly 3 Build system pressure to governor cut out and turn engine OFF 4 Make and hold a full service brake application A Apply asoap solution to the relay valve exhaust port A 1 bubble 3 seconds is permitted B Apply a soap solution to the outside of the modulator body where the relay valve joins the solenoid assembly A 1 bubble in 3 seconds is
21. stall piston 6 into the M 12 modulator body The piston stem fits into the small hole in the center of the body 7 Install o ring 4 onto the protrusion on the bottom of the M 12 modulator solenoid assembly 2 Install the solenoid assembly onto the valve body 3 The solenoid assembly will fit on the M 12 modulator body in any of four orientations 90 degrees apart Secure the solenoid assembly to the valve body with the four 1 2 bolts Torque the bolts to 120 150 in Ibs 8 Install gasket 7 onto the EC 11 controller Install the EC 11 controller 1 as shown in Figure 9 by plugging the 4 pin electrical connector from the solenoid assembly into the socket in the bottom of the controller Press in until lock tab engages Ensure engagement by pulling the connector lightly Place the controller on to the solenoid assembly and secure with the four 1 2 bolts and lockwashers Torque to 30 60 in Ibs DIAGNOSING AND LOCATING A SYSTEM PROBLEM GENERAL The EC 11 controller contains self test and diagnostic circuitry that continuously checks for proper operation of the entire antilock system including wiring continuity Adash light controlled by the EC 11 controller advises the driver of the antilock system condition Specific component condition is provided by a series of Light Emitting Diodes LEDs displayed through a window in the EC 11 controller housing The dash light s separation from the EC 11
22. tion of the body is acceptable Inspect the bores for deep scuffing or gouges Inspect the pipe threads in the body Make certain they are clean and free of thread sealant 5 Inspect all air line fittings and plugs for corrosion Clean all old thread sealant from the pipe threads Any component exhibiting a condition described in inspection steps 2 to 5 should be discarded and replaced before proceeding ASSEMBLY 1 Using a lubricant Bendix Pc No 291126 lightly coat all o rings and the bores of the valve body 2 Install spring seat 9 onto the inlet exhaust valve 8 so that it covers the rubber seat of the inlet exhaust valve Place the inlet exhaust valve large diameter first into the M 12 modulator s bottom bore 3 Install spring 10 over the barrel of the inlet exhaust valve 8 so that one end of the spring rests on the spring seat 9 4 Install the o rings 11 12 into the respective grooves of the O D and I D of the exhaust assembly 13 Place the large diameter ofthe exhaust assembly against the spring 10 and compress the spring until the exhaust assembly enters the bore ofthe body and the o ring 11 seals against the wall of the bore 5 Depress the exhaust assembly into the bore until it exposes the groove for the snap ring 14 Install snap ring 14 into its groove Make sure it is fully seated CAP SCREW TTT E FIGURE 7 EXPLODED VIEW 6 Install o ring 5 into its groove in the piston 6 In
Download Pdf Manuals
Related Search