Bendix Commercial Vehicle Systems ATR-1 ANTILOCK TRACTION RELAY 02/11 User Manual

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Bendix® A TR-1™ AntiLock Traction Relay Valve

TRACTION

CONTROL

SOLENOID

MOUNTING

UNDRILLED

“CON” PORT

SUPPLY

PORT

DELIVERY PORTS (4)

2 PIN SOLENOID

CONNECTOR

COVER PLATE FOR

REMOTE MOUNT

REMOTE MOUNT ATR-1™ RELAY VALVE

BRACKET

BODY

SUPPLY

SERVICE

PORT

SD-13-4811

CONTROLLER MOUNTING

HOLES (4)

SERVICE

PORT

UNTAPPED PORTS

ALTERNATE CASTING ON NEWER VALVES (NOTE THAT THE SERVICE PORT LOCATION IS CHANGED)

DESCRIPTION

The A TR-1™ antilock traction relay valve is a specialized air brake valve developed for use on Bendix antilock/traction equipped vehicles.

It is essentially three separate valves working in combination in a single housing. An R-14 relay is the base valve and is ﬁ tted with a modiﬁ ed cover containing a double check valve and a traction control solenoid. The A TR-1

™

valve contains both air and electric components to provide the service braking and traction control (differential braking) functions. A Bendix antilock traction controller can be mounted to the ATR-1 a cover plate can be installed and the antilock controller mounted elsewhere on the vehicle. When an A TR-1™ valve is combined with an antilock traction controller the resulting assembly is referred to as an antilock traction assembly.

The A TR-1

™

valve replaces the standard relay valve used to control the rear axle service brakes and performs the standard relay function. Like the standard relay valve it replaces, the ATR-1

™

valve (sometimes with attached

antilock controller) is normally mounted near the service

style service

™

valve or

FIGURE 1 - ATR-1™ ANTILOCK TRACTION RELAY VALVE

brakes it serves. A mounting bracket, furnished with the valve, permits either frame or cross member mounting.

™

All air connections on the ATR-1

valve are identiﬁ ed for ease of installation. The letter identiﬁ cation and air line connections are shown below for reference.

ATR-1™ VALVE AIR CONNECTION

EMBOSSED

IDENT.

Supply (to reservoir) SUP Delivery (to brake chamber) DEL Service (to brake valve rear delivery) SER Control (not drilled or threaded on

ATR-1™ valve)

CON

The A TR-1™ valve is part of the R-12® family of relay valves which includes the R-12

, R-14®, BP-R1®, AR-1™.

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 ATR-1™ valve is available with various crack pressures to accommodate speciﬁ c applications, however, the standard is 4 psi.

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OPERATION

GENERAL

Because the A TR-1™ is essentially a relay valve, the following description of operation refers to its function in the vehicles air brake system and does not address all of 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

™

ATR-1

valve.

SERVICE BRAKES APPLYING (FIGURE 4)

Reservoir air pressure is present at the supply port and ﬂ ows through internal body and cover passages to the supply of the normally closed (NC) traction control solenoid.

Brake application air enters the ATR-1 port and is conducted to the single check valve. The check valve diaphragm ﬂ exes in response to application pressure and seals the passage to the open exhaust of the traction solenoid. Air ﬂ ows through the service piston then through the center of the blend back and 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

™

valve’s service

CONTROLLER

ATR-1™ ANTILOCK TRACTION RELAY

VALVE

FIGURE 2 - ANTILOCK TRACTION ASSEMBLY

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 ﬂ ow out the A TR-1

™

valve’s delivery ports to the brake chambers.

SOLENOID

CONNECTOR

BLEND BACK

PISTON

SUPPLY

TRACTION CONTROL

SOLENOID

SERVICE

DOUBLE

CHECK VALVE

RELAY PISTON

INLET-EXHAUST

VALVE

DELIVERY

FIGURE 3 - ATR-1™ ANTILOCK TRACTION ASSEMBLY

EXHAUST

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CONTROLLER

TRACTION SOLENOID

BRAKE

VALVE

CHECK VALVE

RELAY PISTON

REAR AXLE

RESERVOIR

FIGURE 4 - SERVICE BRAKE APPLICATION

SERVICE BRAKES HOLDING (FIGURE 5)

The air pressure being delivered to the brake chambers is also present beneath the relay piston.

When the air pressure above and below the relay piston is equal, the piston moves slightly allowing the inlet valve

CONTROLLER

INLET EXHAUST

MODULATOR

SPRING BRAKE

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.

TRACTION SOLENOID

RELAY PISTON

REAR AXLE

RESERVOIR

FIGURE 5 - SERVICE BRAKES HOLDING

BRAKE

VALVE

CHECK VALVE

INLET EXHAUST

MODULATOR

SPRING BRAKE

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CONTROLLER

TRACTION SOLENOID

RELAY PISTON

REAR AXLE

RESERVOIR

FIGURE 6 - SERVICE BRAKES RELEASING

SERVICE BRAKES RELEASING (FIGURE 6)

When the brake application is released, air from above the relay piston ﬂ ows back through the 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 ATR-1 open exhaust.

™

valve and ﬂ ows out the

BRAKE

VALVE

CHECK VALVE

INLET EXHAUST

MODULATOR

EXHAUST

SPRING BRAKE

TRACTION CONTROL SERVICE BRAKE APPLICATION (FIGURE 7)

GENERAL

While under the control of an antilock traction controller, the ATR-1™ valve’s solenoid is able to initiate a brake application that allows the traction system to control wheel spin upon acceleration under 25 mph. When wheel spin is detected and the vehicle is stopped, or moving at any

CONTROLLER

TRACTION

SOLENOID

RELAY PISTON

REAR AXLE

RESERVOIR

FIGURE 7 - TRACTION CONTROL SERVICE BRAKE APPLICATION

BRAKE

VALVE

CHECK VALVE

INLET EXHAUST

MODULATOR

SPRING BRAKE

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speed up to 25 mph, the antilock traction controller instantly energizes the solenoid in the ATR-1™ valve which then applies air to each of the rear axle modulators as shown in Figure 8. The modulators are equipped with solenoid valves also and because they are also controlled by the controller, the solenoid valves in the appropriate modulator are opened and closed to gently pump the brake on the spinning wheel only . This brake application, to the spinning wheel, forces the differential to drive the stationary or slowly spinning wheel.

OPERATION

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 ATR-1 for signs of wear or physical damage. Replace as necessary.

3. Test air line ﬁ ttings for excessive leakage and tighten or replace as necessary.

4. Perform the Leakage Test described in this manual.

valve

Reservoir air pressure is constantly present at the traction solenoid. When the electronic controller detects wheel spin it energizes the solenoid and in response the solenoid opens momentarily. While the solenoid is open, air is delivered through internal passages to the double check valve. The check valve diaphragm ﬂ exes in response and seals the passage to the open exhaust of the brake valve. Once past the double check valve, air from the solenoid ﬂ ows through the rest of the valve in the same manner as a normal service brake application and air is delivered out the delivery ports of the ATR-1

™

valve.

When the electronic controller de-energizes the solenoid, air between the solenoid and the double check valve returns to the solenoid and is exhausted. Air between the relay piston and double check valve is exhausted at the brake valve while delivery pressure is exhausted at the main A TR-1

™

valve’s exhaust port.

PREVENTIVE MAINTENANCE

Important: Review the warranty policy before performing any intrusive maintenance procedures. An extended warranty may be voided if intrusive maintenance is performed during this period.

Because no two vehicles operate under identical conditions, maintenance intervals will vary. Experience is a valuable guide in determining the best maintenance interval for a vehicle.

GENERAL

Perform the tests and inspections presented at the prescribed intervals. If the ATR-1™ 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 YEAR, 100,000 MILES, OR 3,600 OPERATING HOURS

1. Perform the Operation and Leakage Tests described in this manual.

WARNING! PLEASE READ AND FOLLOW THESE INSTRUCTIONS TO A VOID 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.

2. 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.

3. 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.

4. 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 module, be sure to drain the purge reservoir.

5. Following the vehicle manufacturer’s recommended

procedures, deactivate the electrical system in a manner that safely removes all electrical power from the vehicle.

6. Never exceed manufacturer’s recommended

pressures.

AD-IS® air dryer system or a dryer reservoir

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BRAKE

REAR AXLE

MODULATOR

ANTILOCK

™

AT-30

BRAKE

MODULATOR

REAR AXLE

EXCITER

SPEED SENSOR

MODULATOR

TRACTION ASSY .

VALVE

BRAKE

(ECM)

MODULATOR

TRAILER ABS

TRACTION DASH LAMP

(IF SO EQUIPPED)

ANTILOCK DASH LAMP

TRACTION SWITCH

ENGINE CONTROL MODULE

RETARDER SWITCH

FIGURE 8 - PARTIAL ANTILOCK TRACTION SYSTEM SCHEMATIC

EXCITER

SPEED SENSOR

MODULATOR

BRAKE

CHAMBER

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7. 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.

8. Use only genuine Bendix

brand replacement parts, components and kits. Replacement hardware, tubing, hose, ﬁ ttings, etc. must be of equivalent size, type and strength as original equipment and be designed speciﬁ cally for such applications and systems.

9. Components with stripped threads or damaged parts should be replaced rather than repaired. Do not attempt repairs requiring machining or welding unless speciﬁ cally stated and approved by the vehicle and component manufacturer.

10. Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition.

11. For vehicles with Automatic Traction Control (ATC), the ATC function must be disabled (ATC indicator lamp should be ON) prior to performing any vehicle maintenance where one or more wheels on a drive axle are lifted off the ground and moving.

OPERATION & LEAKAGE TESTS

GENERAL

A change in vehicle braking characteristics or a low pressure warning may indicate a malfunction in one or the other brake circuit, and although the vehicle air brake system may continue to function, the vehicle should not be operated until the necessary repairs have been made and both braking circuits, including the pneumatic and mechanical devices are operating normally. Always check the vehicle brake system for proper operation after performing brake work and before returning the vehicle to service.

OPERATION TEST

™

Note: The ATR-1

valve’s differential pressure can be checked 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 speciﬁ ed for

™

the A TR-1

valve’s part number (see the l.D. washer also for the differential). NOTE: For ATR-1™ valves not incorporating a relay piston return spring(14) the measured differential should be approximately 4 psi. When a spring is in use, the differential will be higher.

2. Disconnect the ATR-1™ valve’s two pin solenoid connector from the controller wire harness. Apply the probes of a volt-ohm meter to the connector leading to the solenoid and note the resistance of the solenoid is between 10 and 12 ohms. If resistance other than this is noted, replace the ATR-1

™

valve.

3. Apply and remove vehicle power (12 vdc) to the two pin connector half leading to the A TR-1™ valve’s (solenoid) while observing the brake chambers. Note that a brake application is made and held while power is applied to the ATR-1

™

valve’s solenoid and that it is released

when power is removed.

LEAKAGE TESTS

1. Build the air system pressure to governor cut-out. Apply a soap solution to the exhaust port. The leakage noted should not exceed a 1” bubble in less than 3 seconds.

2. Make and hold a full brake application and apply a soap solution to the exhaust port and around the cover where it joins the body . The leakage noted should not exceed a 1” bubble in less than 3 seconds at the exhaust port.

If the ATR-1

leakage is excessive, it should be replaced with a new or genuine Bendix remanufactured unit or repaired using a genuine Bendix maintenance kit piece number 109368, available at any authorized parts outlet.

™

valve fails to function as described, or

1. Apply and release the brakes several times and check for prompt application and release at each wheel. If a prompt reaction is noted at some, but not all wheels, test the antilock modulator between the ATR-1™ 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 ATR-1

™

valve. If a complete release of the brakes is noted at some, but not all wheels, test the antilock modulator between the ATR-1

™

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 ATR-1

™

valve.

VEHICLE PREPARATION

1. Park the vehicle on a level surface and block the wheels and/or hold the vehicle by means other than the air brakes.

2. Drain the air pressure from all vehicle reservoirs.

REMOVAL

1. Identify and mark or label all electrical wiring harnesses and air lines and their respective connections on the assembly to facilitate ease of installation.

2. Disconnect the air lines and wire harnesses.

3. Remove the controller and valve assembly from the vehicle.

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PRIOR INTERNAL

COMPONENT

CONFIGURATION

Assembly

of items

29-35

Key Description 1 ECU Control 2 Bolts (4) 3 Cover 4 Base 5 Retaining Ring 6 Exhaust Cover 7 O-Ring

8 O-Ring 9 Valve Spring 10 Valve Retainer 11 Valve Assembly 12 Cap Screws (2) 13 Nuts and Washers (2) 14 Lock Washers (2) 15 Bracket 16 Cap Screws (2) 17 O-Ring 18 O-Ring

Key Description 19 Relay Piston 20 Piston Spring (if used) 21 O-Ring 22 Retaining Ring 23 Check Valve* 24 O-Ring 25 Inlet Seat* 26 Check Valve Seat 27 O-Ring 28 Check Valve 29 Spring Seat 30 Spring 31 Inlet Seat 32 O-Ring 33 O-Ring 34 O-Ring 35 Alternate Plug* 36 Bolts (2)

* Note: For new style ATR-1

both items 23 - 25, or item 35 will be present.

™

valves either

FIGURE 9 - ANTILOCK TRACTION ASSEMBLY EXPLODED VIEW

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INSTALLATION

1. Install the assembled unit on the vehicle.

2. Reconnect all air lines and wire harnesses to the unit using the identiﬁ cation made during REMOVAL step 1.

3. After installing the unit, perform the OPERATION & LEAKAGE TESTS for the air valve before placing the vehicle in service.

DISASSEMBLY

PREPARATION FOR DISASSEMBLY

1. Remove all air ﬁ ttings and plugs from the valve.

2. Mark the relationship of the valve cover(3) to the body(4) and, if the valve is equipped with a mounting bracket(15), mark the relationship of the bracket to the cover and body(4).

3. Mark the relationship of the electronic controller(1) to the cover(3).

DISASSEMBLY

The following disassembly and assembly procedure is presented for reference purposes only. Instructions packaged with repair and maintenance kits should always be followed instead of the instructions presented here.

8. Separate the cover(3) from the body(4), then remove the sealing ring(17) and o-ring(18).

9. Remove the relay piston(19) and relay piston spring(20) from the body(4). NOTE: The relay piston spring, item 14 is not used in all valves.

10. Remove the o-ring(21) from the relay piston(19).

11. Remove the retaining ring(22).

Then, depending on the internal conﬁ guration: 12a. Remove check valve seat(23), with o-rings(27 &

28). Remove o-rings(27 & 28) from the check valve seat. Then remove the check valve(24), guide(25),

and spring(26). OR, 12b. Remove plug(35), with o-ring(34).

13. Remove the inlet seat(29) with o-rings(30 & 31), then

remove o-rings(30 & 31) from the inlet seat(29).

14. Remove the blend back piston(32) from the valve

cover(3). Remove both o-rings(33 & 34) and the piston stop ring(35). Note: The piston stop ring may have to be removed from the cover(3) rather than the piston(32).

15. Do not disassemble the ATR-1™ valve any further than

described here.

CLEANING & INSPECTION

CAUTION: The valve may be lightly clamped in a bench vise during disassembly , however, over clamping will result in 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 body.

1. Remove and retain the four cap screws(2) that secure the electronic controller(1) to the cover(3), then separate and retain the controller(1), from the cover(3). Note: In some instances a controller, Item 1, will not be present and only a cover plate will be noted. Remove the cover plate in the same manner described for the controller.

2. While holding the exhaust cover(6), remove the retaining ring(5) that secures it to the body(4).

3. Remove the exhaust cover(6) along with both o-rings(7 & 8).

4. Remove the valve spring(9), valve retainer(10), and the valve assembly(11) from the body(4).

5. Remove and retain the two long cap screws(12) and nuts(13) that secure the cover(3) to the body(4).

6. Remove and retain the two cap screws and lock washers(14) that secure the bracket(15) to the cover(4), then remove and retain the bracket.

7. Remove and retain the two short cap screws(16) that secure the cover(3) to the body(4).

1. Using mineral spirits or an equivalent solvent, clean and thoroughly dry all metal parts. Do not damage bores with metal tools.

2. Wash all retained, nonmetallic components in a soap and water solution making certain to rinse and dry thoroughly.

3. Inspect the interior and exterior of all metal parts that will be reused for severe corrosion, pitting and cracks. Superﬁ cial corrosion and/or pitting on the exterior portion of the body(4) and cover(3) is acceptable. Replace the entire valve if the interior of the body or cover exhibit signs of corrosion or pitting.

4. Inspect each nonmetallic component for cracks, wear or distortion. Replace the entire valve if these conditions are found.

5. Inspect the bores of both the body(4) and cover(3) for deep scufﬁ ng or gouges. Replace the entire valve if either are found.

6. Make certain the air channel running between the top surface of the body(1) and its supply port is clear and free of obstruction.

7. Make certain all air channels and exhaust passages in the valve cover(3) are clear and free of obstruction.

8. Inspect the pipe threads in the body(4) and valve cover(3). Make certain they are clean and free of thread sealant.

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9. Inspect the relay piston spring(20) for signs of corrosion, pitting and cracks. Replace as necessary.

10. Inspect all air line ﬁ ttings 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 silicone lubricant.

2. Install the piston stop ring(35), then both the large and small diameter o-rings(33 & 34) on the blend back piston(32), then insert the small diameter of the proportioning piston(32) into the bore in the cover(3). Do not cut or pinch the o-rings.

O-Ring Identiﬁ cation

O.D.

I.D.

Key Description Qty . I.D. O.D. W

7 O-Ring 1 0.862 1.068 0.103 8 O-Ring 1 1.424 1.63 0.103 18 O-Ring 1 3.487 3.693 0.103 21 O-Ring 1 3.234 3.512 0.139 27 O-Ring 1 1.362 1.568 0.103 28 O-Ring 1 1.114 1.254 0.07 30 O-Ring 1 1.356 1.496 0.07 31 O-Ring 1 1.176 1.316 0.07 33 O-Ring 1 1.112 1.318 0.103 34 O-Ring 1 0.737 0.943 0.103

(O-rings available in maintenance kit #109368.)

3. Install the small and large diameter o-rings (30 & 31) on the inlet seat(29) then insert the inlet seat into the bore in the cover(2).

Depending on the conﬁ guration/kit being installed: 4a. Install the small and large diameter o-rings (27 & 28) on

the check valve seat(23). Then install the spring(26) on the inlet seat(29) so that the small diameter ﬁ ts over and around the air passage through the center of the inlet seat. Install the check valve(24) and valve guide(25) in the check valve seat(23). Note; The check valve must be installed so that the top hat portion ﬁ ts into the valve seat(23). Install the valve guide(25) so that its ﬂ ange contains (surrounds) the coils of the large end of the spring(26), when the valve seat (23) is installed in the cover(3). Use a small amount of grease to hold these

parts in the valve seat (23). Install the assembled valve seat(23) with the check valve and valve guide(24 & 25) into the cover(3) bore and while holding it in place install the retaining ring(22). Make certain the retaining ring

is fully seated in its groove. OR, 4b. Install the o-ring(34) onto the plug(35). Install into the

cover(3) bore and while holding it in place install the

retaining ring(22). Make certain the retaining ring is

fully seated in its groove.

5. Install the valve retainer(10) on the inlet and exhaust

valve(11) so that the flange of the retainer(10)

surrounds the rubber portion of the valve. Install the

inlet and exhaust valve in the body(4).

6. Install the inlet and exhaust valve return spring(9) in

the body(4).

7. Install the large and small diameter o-rings(7 & 8) in the

exhaust cover(6), then install the exhaust cover in the

body(4) taking care not to damage the o-rings. Hold

the exhaust cover in place.

8. While depressing the exhaust cover(6), install the

retaining ring(5) in the body(4). Make certain the

retainer(5) is fully seated in its groove in the body.

9. If the valve was equipped with a relay piston return

spring(20), install the spring in the body , large diameter

ﬁ rst.

10. Using lubricant to hold them in place, install the large

and small sealing rings(18 & 17) on the cover(3). 1 1. Install the o-ring(21) on the relay piston(19), then install

the piston in the body(4).

12. Note the relationship marks made prior to disassembly ,

then install the cover(3) on the body(4). Secure the

cover on the body using the two, short cap screws(16).

Again, noting the relationship marks, secure the

bracket(15) on the cover(3) and body(4) and using the

two long cap screws(12) and two nuts and washers(13).

Torque the four cap screws to 120 to 150 lb. in.

13. Install the two cap screws(14) that secure the

bracket(15) to the cover(3) and torque to 180-220

pound inches.

14. Noting the relationship marks made during disassembly ,

secure the controller(1) or cover plate to the cover(3)

using the four cap screws(2). Torque the four cap

screws to 50-80 pound inches.

15. Install all air line ﬁ ttings and plugs making certain thread

sealing material does not enter the valve.

16. Install the rebuilt valve on the vehicle and perform the

OPERATION AND LEAKAGE TESTS before placing

the vehicle in service.

Page 11

NOTES

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