BENDIX BW1672 User's Manual
Contents
1. Bendix AR 2 AntiLock Relay Valve ANTILOCK CONTROLLER MOUNTING HOLES 4 MOUNTING BRACKET DELIVERY FIGURE 1 AR 2 ANTILOCK RELAY VALVE ASSEMBLY DESCRIPTION The Bendix AR 2 antilock relay is a specialized air brake valve developed for use on antilock equipped tractors only lt is essentially a BP R1 bobtail brake proportioning relay valve Bendix Service Data Sheet SD 03 1067 with a modified cover that permits direct attachment of a Bendix antilock controller such as the EC 15 When combined with an antilock controller the resulting assembly is referred to as a antilock controller relay assembly For example when the AR 2 valve is combined with the EC 15 electronic controller the resulting assembly is referred to as a CR 16 controller relay assembly While it is intended for use on antilock equipped tractors the AR 2 valve functions solely as an air brake relay and contains no electronics of its own SERVICE CONTROL DELIVERY The AR 2 valve replaces the standard relay valve used to control the rear axle service brakes and performs the standard relay function during tractor trailer operation During tractor bobtail operation the AR 2 valve reduces brake application pressure to the lighter rear axle s brakes to improve vehicle controllability and minimize rear axle s wheel skid before antilock is required The AR 2 valve provides added vehicle braking control and reduces th2. valve on the vehicle and perform the Operation and Leakage Tests before returning the vehicle to service 11 12 BW1672 2011 Bendix Commercial Vehicle Systems LLC All rights reserved 8 11 Printed in the United States
3. After installing the valve and controller assembly test all air fittings for excessive leakage and tighten as needed FIGURE 10 BENDIX AR 2 ANTILOCK RELAY VALVE DISASSEMBLY GENERAL The following disassembly and assembly procedure is presented for reference purposes only and presuppos es that the appropriate maintenance kit is on hand at the time of disassembly The instructions provided with the maintenance kit should always be used in lieu of those presented here Refer to figure 10 throughout the disassembly and assembly procedure CAUTION The Bendix AR 2 valve may be lightly clamped in a bench vise during disassembly however over clamping will cause damage to the valve and result in leakage and or malfunction If a vise is to be used position the valve so that the jaws bear on the supply ports on opposing sides of the valve s body 1 Remove all air fittings and plugs from the AR 2 valve 2 Mark the relationship of the antilock electronic controller 2 and valve cover 4 to the body 9 Note the position of the mounting bracket 6 and mark the relationship of the bracket to the valve body 9 cover 4 and antilock controller 2 Remove and retain the four cap screws and lock washers 1 that secure the controller to the cover 4 then carefully remove the electronic controller without damaging its gasket 3 3 While holding the exhaust cover 11 remove the retaining ring 10 that secures i
4. Install the spring cage 25 in the blend back piston 26 so that its flat side rests against the blend back piston Install the spring 24 in the cage 25 so that its coils are within the D of the cage Insert the service piston 23 in the cover 4 so that the coils of the spring 24 are contained within the piston and the six protruding posts of the piston are visible after the piston is in the cover Install the o ring 22 on the exhaust piston 21 then install the exhaust piston 21 in the cover 4 Refer to the figure and make certain that the exhaust piston 21 is installed with its concave surface away from the service piston 23 While holding the exhaust piston 21 in the cover 4 install the retaining ring 20 making certain it is fully seated in its groove Install the exhaust diaphragm 39 using its screw 37 and washer 38 to retain it Torque the screw to 8 15 pound inches Install the valve retainer 15 on the inlet and exhaust valve 16 so that the flange of the retainer 15 surrounds the rubber portion of the valve Install the inlet and exhaust valve in the body 9 Install the inlet and exhaust valve return spring 14 in the body 9 Install the large and small diameter o rings 13 amp 12 in the cover 11 then install the exhaust cover in the body 9 taking care not to damage the o rings Hold the exhaust cover in place While depressing the exhaust cover 11 install the re
5. 1 Build the air system pressure to governor cut out With the dash mounted trailer supply valve activated for tractor trailer operation apply a soap solution to both exhaust ports one in the cover and one in the body The leakage noted should not exceed a 1 bubble in less than 3 seconds at either exhaust port Make and hold a full brake application and apply a soap solution to both exhaust ports and around the BENDIX AR 2 WITH CONTROLLER va i n a VO ea cover where it joins the body The leakage noted should not exceed a 1 bubble in less than 3 seconds at any exhaust port with no leakage detected between the cover and body VALVE REMOVAL 1 Park the vehicle on a level surface and block the wheels and or hold the vehicle by means other than the air brakes Drain the air pressure from all vehicle reservoirs Identify mark or label all air lines and wiring cables and their respective connections on the valve or antilock controller to facilitate ease of installation Disconnect all air lines and wiring Remove the AR 2 valve and controller assembly from the vehicle VALVE INSTALLATION 1 4 Install all air line fittings and plugs making certain thread sealing material does not enter the valve Install the assembled valve on the vehicle Reconnect all air lines and wiring cables to the valve and controller assembly using the identification made during VALVE REMOVAL step 3
6. 4 psi OPERATION GENERAL Because the AR 2 valve is actually a relay valve the following description of operation refers to its function in the vehicle s air brake system and does not address the separate antilock components and their operation For a description of antilock operation refer to the appropriate Service Data Sheet covering the electronic controller used with the AR 2 valve SD 13 4785 covering the EC 15 electronic controller Other useful information regarding antilock system components used in conjunction with the AR 2 valve are contained in publications SD 13 4793 Bendix M 21 antilock modulator SD 13 4870 Bendix M 32 and M 32QR antilock modulators SD 13 4860 Bendix WS 24 wheel speed sensors and SD 13 4754 Bendix WS 20 wheel speed sensors INITIAL CHARGING During the initial build up of tractor system air pressure reservoir air flows into the supply port and through internal body and cover passages to the blend back piston When sufficient air pressure is applied to the blend back piston it moves against the resistance of its spring until it comes to rest against the service piston Activating the trailer supply valve dash control with red octagonal button simultaneously charges the trailer and the AR 2 valve control port Air entering the AR 2 valve control causes the proportioning piston to move toward its stop in the cover The integral inlet and exhaust valve is
7. LLOW THESEINSTRUCTIONS TOAVOID PERSONAL INJURY OR DEATH When working on or around a vehicle the following general precautions should be observed at all times 1 Parkthe vehicle on a level surface apply the parking brakes and always block the wheels Always wear safety glasses ANTILOCK CONTROLLER BRAKE VALVE VALVE TRAILER SN SUPPLY EE SS SERVICE PROPORTIONING AT al PISTON Paal Wk BLEND BACK PISTON INLET CLOSED EXHAUST CLOSED RELAY PISTON INLET CLOSED EXHAUST CLOSED BENDIX M 21 eee E je REAR AXLE SERVICE CHAMBER FIGURE 7 SERVICE APPLICATION HOLDING BOBTAIL TRACTOR ANTILOCK CONTROLLER TRAILER SUPPLY J gt SERVICE s BRAKE VALVE BENDIX M 21 MODULATOR REAR AXLE SERVICE CHAMBER FIGURE 8 TRACTOR SERVICE BRAKES RELEASING BOBTAIL TRACTOR 6 10 11 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 th
8. VE INLET OPEN EXHAUST OPEN CLOSED in ANTILOCK CONTROLLER b vOLT RESET OL J INLET CLOSED EXHAUST OPEN Coo mu BENDIX M 21 MODULATOR T j lt lt REAR AXLE SERVICE CHAMBER FIGURE 5 TRACTOR SERVICE BRAKES RELEASING TRACTOR TRAILER COMBINATION PREVENTIVE MAINTENANCE GENERAL Perform the tests and inspections presented at the prescribed intervals If the Bendix AR 2 valve fails to function as described or leakage is excessive it should be repaired or replaced with a new or genuine Bendix remanufactured unit available at any authorized parts outlet EVERY 3 MONTHS 25 000 MILES OR 900 OPERATING HOURS 1 Remove any accumulated contaminates and visually inspect the exterior for excessive corrosion and physical damage 2 Inspect all air lines connected to the AR 2 valve for signs of wear or physical damage Replace as necessary 3 Test air line fittings for excessive leakage and tighten or replace as necessary 4 Perform the Leakage Test described in this manual EVERY YEAR 100 000 MILES OR 3 600 OPERATING HOURS 1 Perform the Operation and Leakage Tests described in this manual TRACTOR TRAILER COMBINATION gt BOBTAIL TRACTOR oO ca LLI 2 gt S52 O m LLI Q Sa m 0 PSI BRAKE VALVE DELIVERY PRESSURE AR 27 VALVE SERVICE PORT FIGURE 6 AR 2 VALVE BRAKE PRESSURE DELIVERY WARNING PLEASE READ AND FO
9. action Control ATC the ATC function must be disabled ATC indicator lamp should be ON priorto performing any vehicle maintenance where one or more wheels on a drive axle are lifted off the ground and moving OPERATION amp LEAKAGE TESTS Operation To properly test the function of the Bendix AR 2 valve a pair of test gauges or gauges of known accuracy must be used 1 Install a tee at the AR 2 valve s service port and at one of the delivery ports then install a gauge in each 2 6 Connect the tractor service and emergency glad hands hose couplings to dummy connectors or alternatively to a trailer Build the tractor system air pressure to governor cut out and make 4 to 5 full brake applications Check the air fittings at the AR 2 valve for leakage Tighten as needed With the trailer supply valve dash control with a red octagonal button and system park control dash control with a yellow diamond button activated for tractor trailer operation apply and release the brakes several times and check for prompt application and release at each wheel If prompt reaction is noted at some but not all wheels test the Bendix M 21 antilock modulator between the AR 2 valve and the brake chamber for proper operation If a sluggish response is noted at all wheels inspect for a kinked or obstructed air line leading to or from the AR 2 valve If a complete release of the brakes is noted a
10. carried along with the piston until it seats and seals the exhaust passage Continued movement of the proportioning piston opens the inlet seat With the tractor and trailer air system fully charged the vehicle may be operated TRAILER SUPPLY ANTILOCK a CONTROLLER VALVE INLET OPEN EXHAUST CLOSED SERVICE BRAKE VALVE RELAY PISTON INLET OPEN EXHAUST CLOSED BENDIX M 21 74 MODULATOR Ss lo REAR AXLE SERVICE CHAMBER FIGURE 3 TRACTOR SERVICE BRAKES APPLYING TRACTOR TRAILER COMBINATION SERVICE BRAKES APPLYING TRACTOR TRAILER COMBINATION Brake application air enters the Bendix AR 2 valve service port and is conducted through the service piston then through the center of both the blend back and proportioning pistons to the inlet and exhaust valve Flowing around the inlet valve application air moves through a passage in the cover to the top of the service relay piston In response to air pressure the relay piston moves into contact with the exhaust portion of its inlet and exhaust valve With the exhaust passage sealed continued movement of the piston unseats the inlet portion of the inlet and exhaust valve allowing supply air from the reservoir to flow out the AR 2 valve delivery ports to the brake chambers SERVICE BRAKES HOLDING TRACTOR TRAILER COMBINATION The air pressure being delivered to the brake chambers is also present beneath the relay piston When th
11. e number of times antilock is actually needed Like the standard relay valve it replaces the AR 2 valve and its attached antilock controller is normally mounted near the service brakes it serves A mounting bracket furnished with the valve permits either frame or cross member mounting All air connections on the AR 2 valve are identified with cast embossed letters for ease of identification and installation BLEND BACK PISTON CONTROL PORT EXHAUST INLET EXHAUST VALVE PROPORTIONING PISTON SUPPLY PORT SPRING SERVICE PORT SERVICE PISTON RELAY PISTON SPRING NOT IN ALL MODELS INLET EXHAUST VALVE DELIVERY PORT EXHAUST FIGURE 2 SECTIONAL VIEW BENDIX AR 2 ANTILOCK RELAY VALVE The letter identification and air hose connections are shown below for reference Bendix AR 2 VALVE AIR CONNECTION EMBOSSED IDENT Supply to reservoir SUP Delivery to brake chamber DEL Service to brake valve rear service delivery SER Control to delivery of trailer supply valve CON The AR 2 valve is part of the R 12 family of relay valves which includes the R 12 R 14 BP R1 and AR 1 valves The internal components of the relay portion of all of these valves are interchangeable with the R 12 valve and therefore the same basic components are used to service all of them The AR 2 valve incorporates various crack pressures to accommodate specific applications the standard is
12. e air pressure above and below the relay piston is equal the piston moves slightly allowing the inlet valve to return to its seat The exhaust valve remains closed With both the inlet and exhaust valves closed air pressure in the brake chambers is held stable and neither increases nor decreases SERVICE BRAKES RELEASING TRACTOR TRAILER COMBINATION When the brake application is released air from above the relay piston flows back through the proportioning blend back and service pistons to the foot brake valve and is exhausted As air pressure is reduced above the relay piston pressure beneath it lifts the piston away from the exhaust valve and opens the exhaust passage Air from the service brake chambers returns to the AR 2 valve and flows out the open exhaust SERVICE APPLICATION BOBTAIL TRACTOR When the trailer supply valve dash control with red octagonal button is activated to disconnect the trailer air in the AR 2 valve control port and trailer supply line is exhausted to atmosphere During bobtail tractor operation service application air enters the AR 2 valve service port and as it passes through the blend back piston air exerts a force on the full effective diameter of the piston The blend back piston remains stationary at application pressures below approximately 80 psi because of opposing reservoir air acting on the large diameter Application air flowing through the blend back piston also exerts a force o
13. e proper tools and observe all precautions pertaining to use of those tools If the work is being performed on the 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 vehicle If the vehicle is equipped with a Bendix AD IS air dryer system ora 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 manufacturer s 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 brand 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 For vehicles with Automatic Tr
14. n the small diameter of the proportioning piston while simultaneously flowing through the center of it on its way to the inlet and exhaust valve ANTILOCK CONTROLLER TRAILER SUPPLY VALVE r2 INLET OPEN EXHAUST CLOSED SERVICE BRAKE VALVE RELAY PISTON INLET CLOSED EXHAUST CLOSED BENDIX M 21 MODULATOR REAR AXLE SERVICE CHAMBER FIGURE 4 TRACTOR SERVICE BRAKES HOLDING TRACTOR TRAILER COMBINATION Once past the inlet and exhaust valve service air pressure exerts a force on the larger diameter end of the proportioning piston which opposes the air pressure and spring force exerted on the other end The proportioning piston inlet valve remains open until a preset initial application pressure has reached the relay piston assuring that the foundation brake shoes are brought into contact with the drum As service pressure begins to exceed the preset initial application the proportioning piston will have moved sufficiently to close its inlet valve without opening the exhaust The inlet remains closed preventing additional air delivery to the relay piston and a subsequent increase in brake chamber pressure until service application pressure exceeds approximately 30 psi Service applications above this pressure will result in a proportioned increase of the preset initial brake application to the tractor s rear brakes Proportioning occurs due to the difference in effective area on each end of the p
15. roportioning piston Tractor rear axle brake proportioning will occur for all service applications between approximately 30 and 80 psi Service applications of more than 80 psi cause the blend back piston to begin to move Service air pressure acting on the full diameter of the blend back piston over comes the resistance of reservoir pressure acting on the large diameter of the other side Above 80 psi the ratio between control and delivered air pressure is reduced and blends back from a proportioned delivery to a full 1 to 1 delivery Complete blend back to a 1 for 1 delivery is achieved when a full brake application is made SERVICE BRAKES RELEASING BOBTAIL TRACTOR When the brake application is released all air pressure from between the closed proportioning piston inlet valve and the Bendix AR 2 valve service port returns to the brake valve and is exhausted Air from above the relay piston flows back to the proportioning piston causing it to move As it moves the proportioning piston unseats the exhaust valve allowing air from above the relay piston to escape to atmosphere Reducing the air pressure above the relay piston causes pressure beneath it to lift the piston away from the exhaust valve Air from the service brake chambers returns to the AR 2 valve and flows out the open exhaust a gt IMID b REAR J Ro 1 gt LEFT p MOD p SENS FR z r b TRAILER SUPPLY VAL
16. rtioning piston 30 17 Remove the inlet valve seat 34 the inlet valve 33 and the valve spring 32 from the proportioning piston 30 then remove the o ring 35 from the valve seat 34 18 Remove the exhaust diaphragm screw 37 washer 38 and exhaust diaphragm 39 from the cover 4 CLEANING amp INSPECTION 1 Using mineral spirits or an equivalent solvent clean and thoroughly dry all metal parts 2 Inspect the interior and exterior of all metal parts that will be reused for severe corrosion pitting and cracks Superficial corrosion and or pitting on the exterior portion of the body 9 and cover 4 is acceptable Replace the entire valve if the interior of the body or cover exhibit signs of corrosion or pitting 3 Inspect the bores of both the body 9 and cover 4 for deep scuffing or gouges Replace the entire valve if either are found 4 Make certain all air channels and exhaust passages in the valve cover 4 are clear and free of obstruction 5 Inspect the pipe threads in the body 9 Make certain they are clean and free of thread sealant 6 Wash all non metallic components in a soap and water solution making certain to rinse and dry thoroughly Inspect each non metallic component for cracks wear or distortion Replace the entire valve if these conditions are found 7 If the valve was equipped with a relay piston spring inspect it for signs of corrosion pitting and cracks Replace as neces
17. sary 8 Inspect all air line fittings for corrosion and replace as necessary Make certain to remove all old thread sealant before reuse ASSEMBLY 1 Prior to assembly lubricate all o rings seals and pistons as well as body and cover bores using the lubricant provided with the Bendix maintenance kit Install the o ring 35 on the inlet valve seat 34 3 Insert the inlet and exhaust valve spring 32 LARGE END FIRST into the proportioning piston 30 4 Install the inlet and exhaust valve 33 inside the inlet valve seat 34 making certain that the four tabs are within the bore of the seat 10 11 12 13 14 19 16 17 18 19 Carefully insert the assembled valve 33 and seat 34 into the proportioning piston 30 making certain that the coils of the valve spring 32 rest on the four tabs of the valve 33 While holding the seat 34 in place install the retaining ring 36 to secure it in the piston 30 Make certain the retaining ring is fully seated in its groove Install both the large and small diameter o rings 31 amp 29 on the proportioning piston 30 Install both the large and small diameter o rings 27 amp 28 on the blend back piston 26 then insert the small diameter of the proportioning piston 30 into the small diameter end of the blend back piston 26 Carefully insert the assembled proportioning and blend back pistons 30 amp 26 into the cover 4
18. t some but not all wheels test the M 21 antilock modulator between the AR 2 valve and the brake chamber for proper operation If an incomplete release is noted at all wheels inspect for a kinked or obstructed air line leading to or from the AR 2 valve Check the AR 2 valve s differential pressure by applying 10 psi to the service port and noting the pressure registered at the delivery port Subtract delivery port pressure from the 10 psi service pressure to obtain the differential Compare the measured differential with the pressure specified for the AR 2 valve part number NOTE For AR 2 valves not incorporating a relay piston return spring the measured differential should be approximately 4 psi When a spring is in use the differential will be higher Make and hold a full 100 psi or greater brake application and note that full pressure is delivered to the brake chambers Activate the dash mounted trailer supply valve for bobtail tractor operation Then make a slow brake application increasing the pressure at the AR 2 valve service port to 20 psi while watching the reaction at the delivery port gauge Note that delivery pressure rises to approximately 5 to 10 psi and remains constant while service pressure continues to rise to 20 psi Release the application Make another brake application and slowly increase the pressure at the AR 2 valve service port to between 60 and 70 psi while observing the gauge ins
19. t to the body 9 4 Remove the exhaust cover 11 along with both o rings 12 amp 13 5 Remove the valve spring 14 valve retainer 15 and the valve assembly 16 from the body 9 6 Remove and retain the two cap screws and lock washers 5 that secure the bracket 6 to the cover 4 Remove and retain the two bolts with lock washers 7 and nuts 8 that secure the cover 4 and mounting bracket to the valve body 9 Then remove the remaining two cap screws 7 that secure the cover 4 to the body 9 7 Separate the cover 4 and mounting bracket 6 from the body 9 then remove the large and small sealing rings 19 amp 40 8 Remove and retain the relay piston 17 and relay piston spring if present from the body 9 NOTE The relay piston spring is not used in all AR 2 valves 9 Remove the o ring 18 from the relay piston 17 10 Remove the retaining ring 20 from the cover 4 then remove the exhaust piston 21 11 Remove the exhaust piston o ring 22 12 Remove the service piston 23 from the cover 4 13 Remove the spring 24 and spring cage 25 from the cover 4 14 Remove the blend back piston 26 from the valve cover 4 then remove both o rings 27 amp 28 10 15 Remove the proportioning piston 30 from the valve cover 4 then remove both o rings 29 amp 31 16 While holding the inlet valve seat 34 in place remove the retaining ring 36 from the propo
20. taining ring 10 in the body 9 Make certain the retainer 10 is fully seated in its groove in the body If the Bendix AR 2 valve was equipped with a relay piston return spring install the spring in the body large diameter first 20 21 862 1 424 3 487 3 234 1 356 1 112 O RING IDENTIFICATION CHART 1 068 1 630 3 693 3 512 1 496 1 318 TTi 412 139 489 943 02 879 629 Using lubricant to hold them in place install the large diameter sealing ring 19 on the cover 4 and the small diameter sealing ring 40 on the body 9 Install the o ring 18 on the relay piston 17 then install the piston in the body 9 22 After noting the relationship marks made prior to 23 24 23 disassembly install the cover 4 on the body 9 Secure the cover to the body using the two shortest cap screws and lock washers 7 Make certain the sealing rings 19 amp 40 remain in place Torque the cap screws to 120 150 pound inches Secure the mounting bracket 6 to the cover 4 using the cap screws and lock washers 5 and torque the cap screws to 180 220 pound inches Then secure the mounting bracket 6 to the body 9 and cover 4 using the two longest cap screws and lock washers 7 and nuts 8 and torque the cap screws to 120 150 pound inches Install all air line fittings and plugs making certain thread sealing material does not enter the valve Install the AR 2
21. talled at the delivery port Note that when service port pressure rises to between 20 and 30 psi delivery pressure begins to rise above the initial pressure noted in step 6 The rise of delivery pressure should be at a proportioned rate of approximately 3 to 1 For example Each 3 psi increase at the service port results in a delivery pressure increase of 1 psi At 70 psi service port pressure brake chamber pressure should be 15 to 25 psi DASH CONTROL VALVES TRACTOR PROTECTION BRAKE VALVE BENDIX M 21 MODULATORS FIGURE 9 TYPICAL BENDIX CR 16 AIR BRAKE SYSTEM 8 Make a full brake application and note that both test gauges register the same pressure IMPORTANT If during testing the service port pressure is SLOWLY increased from approximately 70 psi to a full 100 psi or greater brake application the Bendix AR 2 valve MAY begin to cycle between an apply and exhaust mode This condition is normal while the AR 2 valve is transitioning from the proportioning mode to the full delivery mode and will only occur if the service application is SLOWLY increased as described Cycling will not occur or can be stopped by increasing or decreasing service port pressure Remove the test gauges from the AR 2 valve If the AR 2 valve fails to perform as described it should be replaced or repaired using genuine Bendix replacement parts or kits LEAKAGE TESTS
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