Instruction Manual

ManualsBrandsBendix Commercial Vehicle Systems ManualsEquipmentATR-3 ANTILOCK TRAC RELAY VLV

FIGURE 1 - BENDIX

ATR-6

™

(AND ATR-3

™

) ANTILOCK TRACTION RELAY VALVES

DESCRIPTION

This Service Data sheet covers the operation, and

replacement procedures, for both the Bendix

ATR-6

™

and

the previous ATR-3

™

Antilock Traction Relay valves. These

valves are specialized air brake valves developed for use

on Bendix antilock/traction-equipped vehicles.

This document will refer to the ATR-6

™

Antilock Traction

Relay valve throughout since the ATR-3

™

version operates

in an almost identical way. See Figure 1 for external

differences.

The ATR-6

™

Antilock Traction Relay valve is a service

relay valve ﬁ tted with a modiﬁ ed cover containing a Control

Solenoid. It contains both air and electric components to

provide the service braking and traction control (differential

braking) as well as ESP

advanced stability system ABS

functions.

Typically the ATR-6

™

valve replaces a standard relay valve

used to control the rear axle service brakes, though it may

be used for both front and rear axles on some advanced

ABS vehicle applications. In normal operation, it performs

the standard relay function and like the standard relay valve

it replaces, the ATR-6

™

valve is normally mounted near the

service brakes it serves.

When the ABS Controller operates the ATR-6

™

valve, for

example during an antilock traction event, the Control

Solenoid is energized and permits delivery air to be

supplied to the Antilock Modulator Valves and used as

required by the Controller - see Operation below for a full

explanation.

For ease of servicing, the inlet/exhaust valve can be

replaced without the need to remove the entire valve.

All air connections on the ATR-6

™

valve are identiﬁ ed as

shown below.

Bendix

ATR-6

™

Antilock Traction Relay Valve

AIR CONNECTION EMBOSSED IDENT.

Supply (to reservoir) . . . . . . . . . . . . . . . . .SUP (1)

Delivery (to brake chamber) . . . . . . . . . . DEL (2)

Control (to brake valve rear delivery) . . CON (4)

The ATR-6

™

valve is part of the R-12

™

family of relay valves.

The internal components of the relay portion of all of these

valves are interchangeable with the R-12

™

valve and the

same basic components are used to service all of them.

The ATR-6

™

valve is available with various crack pressures

(the control pressure required to initiate air delivery to the

brakes) to accommodate speciﬁ c vehicle applications;

however the standard is 4 psi (see Figure 7 on Page 5).

SD-13-4861

Bendix

ATR-6

™

and ATR-3

™

Antilock Traction Relay Valves

Bendix

ATR-6

™

Antilock

Traction Relay Valves

Bendix

ATR-3

™

Antilock

Traction Relay Valves

CONTROL

PORT

DELIVERY PORTS (6)

2 PIN

SOLENOID

CONNECTOR

SUPPLY

PORT

COVER

CONTROL

SOLENOID

ESP

is a registered trademark of Daimler and is used by BCVS under license.

Summary of content (8 pages)

PAGE 1
SD-13-4861 Bendix® ATR-6™ and ATR-3™ Antilock Traction Relay Valves Bendix® ATR-3™ Antilock Traction Relay Valves 2 PIN SOLENOID CONNECTOR CONTROL SOLENOID CONTROL PORT COVER Bendix® ATR-6™ Antilock Traction Relay Valves SUPPLY PORT DELIVERY PORTS (6) FIGURE 1 - BENDIX® ATR-6™ (AND ATR-3™) ANTILOCK TRACTION RELAY VALVES DESCRIPTION This Service Data sheet covers the operation, and replacement procedures, for both the Bendix® ATR-6™ and the previous ATR-3™ Antilock Traction Relay valves.
PAGE 2
Control Shuttle. The small piston (shown in its normal rest position). The arrow indicates spring force holding it in position.
PAGE 3
The pressure under the piston equals the pressure above. The piston lifts slightly - the exhaust remains closed. FIGURE 4 - BRAKE APPLICATION HOLDING EXHAUST (OR RELEASE) See Figure 5. When the driver releases the brake pedal, air pressure above the relay piston is exhausted at the brake valve exhaust. At the same time, air pressure beneath the piston lifts the relay piston and the exhaust seat moves away from the exhaust valve, opening the exhaust passage at the base of the relay valve.
PAGE 4
For a full description of antilock operation refer to the appropriate Service Data Sheet covering the Electronic Controller used on the vehicle. (Note: Service Data Sheets are available for download from www.bendix.com.) 5. Following the vehicle manufacturer’s recommended procedures, deactivate the electrical system in a manner that safely removes all electrical power from the vehicle. PREVENTIVE MAINTENANCE 6. Never exceed manufacturer ’s recommended pressures.
PAGE 5
Key No. 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8 . 9 . 10. 11. 12. 13. 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Washer Identifying Crack Pressure Description . . . . . . . . . . . . . . . Valve Cover . O-ring . O-ring . Relay Piston . Valve Body . Inlet & Exhaust Valve . Valve Retainer . Spring . O-ring . O-ring . Exhaust Cover . Retaining Ring . Differential Spring (If Used) .
PAGE 6
Caution: Drain all reservoirs before attempting to remove the inlet exhaust valve. Replace all parts not considered serviceable during these inspections and all springs and rubber parts. Use only genuine Bendix replacement parts, available from any authorized Bendix parts outlet. DISASSEMBLY ASSEMBLY Note: Prior to disassembly, mark the location of the mounting bracket (not shown) to the cover and the cover to the body.
PAGE 7
5. Test valve as outlined in Operational and Leakage Tests. OPERATIONAL AND LEAKAGE TESTS 1. Chock the wheels, fully charge air brake system and adjust the brakes. 2. Make several brake applications and check for prompt application and release at each wheel. 3. Check for inlet valve and O-ring leakage. Make this check with the service brakes released. Coat the exhaust port and the area around the retaining ring with a soap solution; leakage of a one-inch bubble in 3 seconds is permitted. 4.