Bendix Commercial Vehicle Systems ATR-3 ANTILOCK TRAC RELAY VLV - Manual

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 .