1
®
SD-13-481
1
A
DESCRIPTION
The ATR-1DC
™
antilock traction relay valve is a specialized
air brake valve developed for use on Bendix antilock/traction
equipped vehicles. The ATR-1DC
™
valve can be used on
straight trucks, buses and tractors. Although this valve, in
combination with the appropriate controller, can be used
in any Bendix antilock traction equipped brake system, it
was developed for use in systems that were built to comply
with Federal regulations effective 3/1/98.
It is a combination of four separate valves working in a single
housing. A Bendix
®
R-14
™
service relay is the base valve,
fitted with a modified cover containing two double check
valves and a traction control solenoid. In addition, the
ATR-1DC
™
valve also incorporates a relay piston drain, which
continually allows system contamination to be drained from
the relay exhaust port. (Refer to Service Data Sheet for
more information.)
The ATR-1DC
™
valve contains both air and electric
components to provide the service braking and traction
control (differential braking) functions. The traction function
of the ATR-1DC
™
valve is enhanced to allow coordination
with the air suspension system of a 6x2 vehicle.
A Bendix antilock traction controller, such as the EC-16
™
or
EC-17
™
, can be mounted to the ATR-1DC
™
valve or a cover
plate can be installed and the antilock controller mounted
elsewhere on the vehicle. When an ATR-1DC
™
valve is
combined with an antilock traction controller the resulting
assembly is referred to as a antilock traction assembly or
AT-1DC
™
.
The ATR-1DC
™
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-1DC
™
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-1DC
™
valve are identified with
cast, embossed letters for ease of identification and
installation. The letter identification and air line connections
are shown below for reference.
EMBOSSED ATR-1DC AIR CONNECTION
IDENT.
Supply (to reservoir)
SUP
Delivery (to brake Chamber)
DEL
Primary Control (to brake valve rear delivery)
4 1
Secondary Control
4 2
(to brake valve front delivery)
Optional Auxiliary
2 1
(connected to air suspension control)
Bendix
®
ATR-1DC
™
AntiLock Traction Relay Valve
MOUNTING
BRACKET
CONTROLLER
MOUNTING HOLES (4)
REMOTE MOUNT ATR-1DC
™
VALVE
TRACTION CONTROL
SOLENOID
SECONDARY
CONTROL
PORT
4 2
(1)
DELIVERY
PORT (4)
2 PIN SOLENOID
CONNECTOR
SUPPLY
PORT
(2)
FIGURE 1 - ATR-1DC
™
ANTILOCK TRACTION RELAY VALVE
PRIMARY
CONTROL
PORT
4 1
(1)
AUXILIARY
CONTROL
PORT
2 1
(1)
COVER PLATE FOR
REMOTE MOUNT
REVERSE
ANGLE
VIEW
