BENDIX ar-2 antilock relay valve Manuel D’Utilisation

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FIGURE 1 - AR-2

™

 ANTILOCK RELAY VALVE ASSEMBLY

The AR-2

™

 antilock relay is a specialized air brake valve

developed for use on antilock equipped tractors only. It is
essentially a BP-R1

™

 “bobtail” brake proportioning relay valve

(Bendix Service Data Sheet SD-03-1067) with a modified
cover that permits direct attachment of a Bendix

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 antilock

controller such as the EC-15

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. When combined with an

antilock controller the resulting assembly is referred to as a
antilock controller relay assembly. For example when the
AR-2

™

 valve is combined with the EC-15

™

 electronic

controller, the resulting assembly is referred to as a CR-16

™

controller relay assembly.

While it is intended for use on antilock equipped tractors,
the AR-2

™

 valve functions solely as an air brake relay and

contains no electronics of its own.

The AR-2

™

 valve replaces the standard relay valve used to

control the rear axle service brakes and performs the standard
relay function during tractor-trailer operation. During tractor
bobtail operation, the AR-2

™

 valve reduces brake application

pressure to the lighter rear axle(s) brakes to improve vehicle
controllability and minimize rear axle(s) wheel skid before
antilock is required. The AR-2

™

 valve provides added vehicle

braking control and reduces the number of times antilock is
actually needed.

Like the standard relay valve it replaces, the AR-2

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 valve

and its 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 AR-2

™

 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.

ANTILOCK CONTROLLER

MOUNTING HOLES(4)

DELIVERY

SUPPLY

DELIVERY

MOUNTING

BRACKET

CONTROL

SERVICE