User's Manual

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SD-13-4811

DESCRIPTION

The ATR-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

style service

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 ATR-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

™

valve or

a cover plate can be installed and the antilock controller

mounted elsewhere on the vehicle. When an ATR-1

™

valve

is combined with an antilock traction controller the resulting

assembly is referred to as an antilock traction assembly.

The ATR-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

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 ATR-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.

Bendix

ATR-1

™

AntiLock Traction Relay Valve

SUPPLY

PORT

BODY

MOUNTING

BRACKET

SERVICE

PORT

CONTROLLER MOUNTING

HOLES (4)

UNTAPPED PORTS

COVER PLATE FOR

REMOTE MOUNT

ATR-1

™

RELAY

VALVE

ALTERNATE

CASTING ON

NEWER VALVES

(NOTE THAT THE

SERVICE PORT

LOCATION IS

CHANGED)

UNDRILLED

“CON” PORT

DELIVERY

PORTS (4)

2 PIN SOLENOID

CONNECTOR

SUPPLY

PORT

FIGURE 1 - ATR-1

™

ANTILOCK TRACTION RELAY VALVE

TRACTION

CONTROL

SOLENOID

SERVICE

PORT

Summary of content (12 pages)

PAGE 1
SD-13-4811 ® Bendix ATR-1 AntiLock Traction Relay Valve ™ TRACTION CONTROL SOLENOID MOUNTING BRACKET UNDRILLED “CON” PORT CONTROLLER MOUNTING HOLES (4) SERVICE PORT SUPPLY PORT DELIVERY PORTS (4) 2 PIN SOLENOID CONNECTOR COVER PLATE FOR REMOTE MOUNT REMOTE MOUNT ATR-1™ RELAY VALVE DESCRIPTION The ATR-1™ antilock traction relay valve is a specialized air brake valve developed for use on Bendix antilock/traction equipped vehicles.
PAGE 2
OPERATION GENERAL CONTROLLER ™ Because the ATR-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.
PAGE 3
CONTROLLER BRAKE VALVE TRACTION SOLENOID CHECK VALVE RELAY PISTON INLET EXHAUST MODULATOR REAR AXLE RESERVOIR SPRING BRAKE 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 to return to its seat. The exhaust valve remains closed.
PAGE 4
CONTROLLER BRAKE VALVE TRACTION SOLENOID CHECK VALVE RELAY PISTON INLET EXHAUST MODULATOR REAR AXLE RESERVOIR EXHAUST SPRING BRAKE FIGURE 6 - SERVICE BRAKES RELEASING SERVICE BRAKES RELEASING (FIGURE 6) When the brake application is released, air from above the relay piston flows back through the blend back and service pistons to the foot brake valve and is exhausted.
PAGE 5
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.
PAGE 6
FIGURE 8 - PARTIAL ANTILOCK TRACTION SYSTEM SCHEMATIC 6 BRAKE CHAMBER RETARDER SWITCH TRACTION SWITCH ANTILOCK DASH LAMP TRACTION DASH LAMP TRAILER ABS (IF SO EQUIPPED) EXCITER SPEED SENSOR MODULATOR MODULATOR ENGINE CONTROL MODULE (ECM) BRAKE VALVE EXCITER SPEED SENSOR AT-30™ ANTILOCK TRACTION ASSY.
PAGE 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, fittings, etc. must be of equivalent size, type and strength as original equipment and be designed specifically for such applications and systems. 9.
PAGE 8
35 2 34 33 32 1 PRIOR INTERNAL COMPONENT CONFIGURATION 12 31 16 30 29 28 27 25 Assembly of items 29-35 34 3 22 21 19 35 22 20 17 4 24 23 18 14 15 Key 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Description ECU Control Bolts (4) Cover Base Retaining Ring Exhaust Cover O-Ring O-Ring Valve Spring Valve Retainer Valve Assembly Cap Screws (2) Nuts and Washers (2) Lock Washers (2) Bracket Cap Screws (2) O-Ring O-Ring Key 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Description R
PAGE 9
INSTALLATION 1. Install the assembled unit on the vehicle. 2. Reconnect all air lines and wire harnesses to the unit using the identification 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. 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).
PAGE 10
9. Inspect the relay piston spring(20) for signs of corrosion, pitting and cracks. Replace as necessary. 10. Inspect all air line fittings for corrosion and replace as necessary. Make certain to remove all old thread sealant before reuse. 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.
PAGE 11
NOTES 11