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®
Bendix® AR-2™ AntiLock Relay Valve
ANTILOCK CONTROLLER
MOUNTING HOLES(4)
MOUNTING
BRACKET
SD-13-4796
SERVICE
SUPPLY
DELIVERY
FIGURE 1 - AR-2™ ANTILOCK RELAY VAL VE ASSEMBLY
DESCRIPTION
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® antilock
controller such as the EC-15™. 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.
DELIVERY
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™ 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.
CONTROL
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BLEND BACK
PISTON
SPRING
CONTROL PORT
EXHAUST
INLET/EXHAUST VALVE
PROPORTIONING
PISTON
SUPPLY PORT
EXHAUST
FIGURE 2 - SECTIONAL VIEW AR-2™ ANTILOCK RELAY VAL VE
SERVICE PORT
SERVICE PISTON
RELAY PISTON
SPRING (NOT IN ALL
MODELS)
INLET/EXHAUST VALVE
DELIVERY PORT
AR-2™ VALVE
AIR CONNECTION EMBOSSED IDENT .
Supply (to reservoir) SUP
Delivery (to brake chamber) DEL
Service (to brake valve rear service delivery) SE R
Control (to delivery of trailer supply valve) CO N
The AR-2™ valve is part of the R-12™ family of relay valves
which includes the R-12™, R-14™, BP-R1™, and AR-1™ valves.
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 AR-2™ valve incorporates various crack pressures to
accommodate specific applications, the standard is 4 psi.
OPERATION
GENERAL
Because the AR-2™ valve is actually a relay valve, the
following description of operation refers to its function in the
vehicle’s air brake system and does not address 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 AR-2
valve (ie; SD-13-4785 covering the EC-15™ electronic
controller). Other useful information regarding antilock
system components used in conjunction with the AR-2
valve is contained in publications SD-13-4793 covering the
M-21™ antilock modulator and SD-13-4754 covering the
WS-20™ wheel speed sensor.
INITIAL CHARGING
During the initial build up of tractor system air pressure,
reservoir air flows into the supply port and through internal
body and cover passages to the blend back piston. When
sufficient air pressure is applied to the blend back piston, it
moves against the resistance of its spring until it comes to
rest against the service piston.
Activating the trailer supply valve (dash control with red
octagonal button), simultaneously charges the trailer and
the AR-2™ valve control port. Air entering the AR-2™ valve
control causes the proportioning piston to move toward its
stop in the cover. The integral inlet and exhaust valve is
carried along with the piston until it seats and seals the
exhaust passage. Continued movement of the proportioning
piston opens the inlet seat. With the tractor and trailer air
system fully charged the vehicle may be operated.
™
™
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TRAILER
SUPPLY
VALVE
INLET-OPEN
EXHAUST-CLOSED
REAR AXLE
SERVICE
CHAMBER
ANTILOCK
CONTROLLER
SERVICE
BRAKE
VALVE
RELAY PISTON
INLET-OPEN
EXHAUST-CLOSED
™
M-21
MODULATOR
FIGURE 3 - TRACTOR SERVICE BRAKES APPL YING - TRACTOR TRAILER COMBINATION
SERVICE BRAKES APPLYING - TRACTOR/TRAILER
COMBINA TION
Brake application air enters the AR-2™ valve service port
and is conducted through the service piston then through
the center of both the blend back and proportioning pistons
to the inlet and exhaust valve. Flowing around the inlet valve,
application air moves through a passage in the cover to the
top of the service relay piston. In response to air pressure,
the relay piston moves into contact with the exhaust portion
of its inlet and exhaust valve. With the exhaust passage
sealed, continued movement of the piston unseats the inlet
portion of the inlet and exhaust valve, allowing supply air
from the reservoir to flow out the AR-2™ valve delivery ports
to the brake chambers.
SERVICE BRAKES RELEASING - TRACTOR/TRAILER
COMBINA TION
When the brake application is released, air from above the
relay piston, flows back through the proportioning, blend
back and service pistons to the foot brake valve and is
exhausted. As air pressure is reduced above the relay
piston, pressure beneath it lifts the piston away from the
exhaust valve and opens the exhaust passage. Air from the
service brake chambers returns to the AR-2™ valve and flows
out the open exhaust.
SERVICE APPLICATION - BOBT AIL TRACTOR
When the trailer supply valve (dash control with red octagonal
button) is activated to disconnect the trailer, air in the AR-2
valve control port and trailer supply line is exhausted to
SERVICE BRAKES HOLDING - TRACTOR/TRAILER
COMBINA TION
The air pressure being delivered to the brake chambers is
also present beneath the relay piston.
When the air pressure above and below relay piston is
equal, the piston moves slightly allowing the inlet valve to
return to its seat. The exhaust valve remains closed. With
both the inlet and exhaust valves closed, air pressure in the
brake chambers is held stable and neither increases nor
atmosphere. During bobtail tractor operation, service
application air enters the AR-2™ valve service port and as it
passes through the blend back piston air exerts a force on
the full effective diameter of the piston. The blend back piston
remains stationary at application pressures below
approximately 80 psi because of opposing reservoir air
acting on the large diameter. Application air flowing through
the blend back piston also exerts a force on the small
diameter of the proportioning piston while simultaneously
decreases.
™
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ANTILOCK
CONTROLLER
TRAILER
SUPPLY
VALVE
INLET-OPEN
EXHAUST-CLOSED
REAR AXLE
SERVICE
CHAMBER
FIGURE 4 - TRACTOR SERVICE BRAKES HOLDING - TRACTOR TRAILER COMBINATION
SERVICE
BRAKE
VALVE
RELAY PISTON
INLET-CLOSED
EXHAUST-CLOSED
™
MODULATOR
M-21
flowing through the center of it on its way to the inlet and
exhaust valve.
Once past the inlet and exhaust valve, service air pressure
exerts a force on the larger diameter end of the proportioning
piston, which opposes the air pressure and spring force
exerted on the other end. The proportioning piston inlet
valve remains open until a preset, initial application pressure
has reached the relay piston assuring that the foundation
brake shoes are brought into contact with the drum. As
service pressure begins to exceed the preset initial
application, the proportioning piston will have moved
sufficiently to close its inlet valve without opening the
exhaust.
The inlet remains closed, preventing additional air delivery
to the relay piston and a subsequent increase in brake
chamber pressure, until service application pressure
exceeds approximately 30 psi. Service applications above
this pressure will result in a proportioned increase of the
preset initial brake application to the tractor’s rear brakes.
Proportioning occurs due to the difference in effective area
on each end of the proportioning piston. Tractor rear axle
brake proportioning will occur for all service applications
between approximately 30 and 80 psi.
4
Service applications of more than 80 psi cause the blend
back piston to begin to move. Service air pressure acting
on the full diameter of the blend back piston over comes
the resistance of reservoir pressure acting on the large
diameter of the other side. Above 80 psi the ratio between
control and delivered air pressure is reduced and “blends
back” from a proportioned delivery to a full 1 to 1 delivery .
Complete “blend back” to a 1 for 1 delivery is achieved
when a full brake application is made.
SERVICE BRAKES RELEASING - BOBT AIL TRACT OR
When the brake application is released, all air pressure from
between the closed proportioning piston inlet valve and the
AR-2™ valve service port returns to the brake valve and is
exhausted. Air from above the relay piston, flows back to
the proportioning piston causing it to move. As it moves, the
proportioning piston unseats the exhaust valve allowing air
from above the relay piston to escape to atmosphere.
Reducing the air pressure above the relay piston, causes
pressure beneath it to lift the piston away from the exhaust
valve. Air from the service brake chambers returns to the
AR-2™ valve and flows out the open exhaust.
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ANTILOCK
CONTROLLER
TRAILER
SUPPLY
VALVE
INLET-OPEN
EXHAUST-OPEN/CLOSED
INLET-CLOSED
EXHAUST-OPEN
REAR AXLE SERVICE
CHAMBER
FIGURE 5 - TRACTOR SERVICE BRAKES RELEASING - TRACTOR TRAILER COMBINA TION
™
M-21
MODULATOR
SERVICE
BRAKE
VALVE
PREVENTIVE MAINTENANCE
GENERAL
Perform the tests and inspections presented at the
prescribed intervals. If the AR-2™ valve fails to function as
described, or leakage is excessive, it should be repaired or
replaced with a new or genuine Bendix remanufactured
unit, available at any authorized parts outlet.
EVERY 3 MONTHS, 25,000 MILES OR 900 OPERATING
HOURS
1. Remove any accumulated contaminates and visually
inspect the exterior for excessive corrosion and physical
damage.
2. Inspect all air lines connected to the AR-2™ valve for
signs of wear or physical damage. Replace as necessary .
3. T est air line fittings for excessive leakage and tighten or
replace as necessary.
4. Perform the Leakage Test described in this manual.
EVERY YEAR, 100,000 MILES, OR 3,600 OPERATING
HOURS
1. Perform the Operation and Leakage T ests described in
this manual.
TRACTOR
TRAILER
COMBINATION
BOBTAIL
TRACTOR
PRESSURE
BRAKE CHAMBER
0 PSI
FIGURE 6 - AR-2™ VA L VE BRAKE PRESSURE DELIVERY
BRAKE VALVE DELIVERY PRESSURE
™
(AR-2
VALVE SERVICE PORT)
WARNING! PLEASE READ AND FOLLOW
THESE INSTRUCTIONS TO AVOID
PERSONAL INJURY OR DEATH:
When working on or around a vehicle, the following
general precautions should be observed at all times.
1. Park the vehicle on a level surface, apply the
parking brakes, and always block the wheels.
Always wear safety glasses.
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ANTILOCK
CONTROLLER
TRAILER
SUPPLY
VALVE
PROPORTIONING
PISTON
INLET-CLOSED
EXHAUST-CLOSED
FIGURE 7 - SERVICE APPLICA TION HOLDING - BOBT AIL TRACT OR
SERVICE
BRAKE
VALVE
BLEND BACK
PISTON
RELAY PISTON
INLET-CLOSED
EXHAUST-CLOSED
M-21™ MODULATOR
REAR AXLE SERVICE
CHAMBER
TRAILER
SUPPLY
VALVE
ANTILOCK
CONTROLLER
SERVICE
BRAKE
VALVE
™
MODULATOR
M-21
REAR AXLE SERVICE
CHAMBER
FIGURE 8 - TRACTOR SERVICE BRAKES RELEASING - BOBT AIL TRACTOR
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2. Stop the engine and remove ignition key when
working under or around the vehicle. When
working in the engine compartment, the engine
should be shut off and the ignition key should be
removed. Where circumstances require that the
engine be in operation, EXTREME CAUTION should
be used to prevent personal injury resulting from
contact with moving, rotating, leaking, heated or
electrically charged components.
3. Do not attempt to install, remove, disassemble or
assemble a component until you have read and
thoroughly understand the recommended
procedures. Use only the proper tools and observe
all precautions pertaining to use of those tools.
4. If the work is being performed on the vehicle’s air
brake system, or any auxiliary pressurized air
systems, make certain to drain the air pressure
from all reservoirs before beginning
ANY work on
the vehicle. If the vehicle is equipped with an
AD-IS™ air dryer system or a dryer reservoir module,
be sure to drain the purge reservoir.
5. Following the vehicle manufacturer’s
recommended procedures, deactivate the electrical
system in a manner that safely removes all electrical
power from the vehicle.
6. Never exceed manufacturer’s recommended
pressures.
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® 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. Components with stripped threads or damaged
parts should be replaced rather than repaired. Do
not attempt repairs requiring machining or welding
unless specifically stated and approved by the
vehicle and component manufacturer.
10. Prior to returning the vehicle to service, make
certain all components and systems are restored to
their proper operating condition.
OPERATION & LEAKAGE TESTS
Operating T est
T o properly test the function of the AR-2™ valve, a pair of test
gauges or gauges of known accuracy must be used.
1. Install a “tee” at the AR-2™ valve’s service port and at
one of the delivery ports, then install a gauge in each.
2. Connect the tractor service and emergency “glad hands”
(hose couplings) to dummy connectors, or alternatively,
to a trailer. Build the tractor system air pressure to
governor cut-out and make 4 to 5 full brake applications.
Check the air fittings at the AR-2™ valve for leakage.
Tighten as needed.
3. With the trailer supply valve (dash control w/red octagonal
button) and system park control (dash control w/yellow
diamond button) activated for tractor/trailer operation,
apply and release the brakes several times and check
for prompt application and release at each wheel. If
prompt reaction is noted at some, but not all wheels,
test the M-21™ antilock modulator between the AR-2
valve and the brake chamber for proper operation. If a
“sluggish” response is noted at all wheels, inspect for a
kinked or obstructed air line leading to or from the AR-2
valve. If a complete release of the brakes is noted at
™
some, but not all wheels, test the M-21
modulator between the AR-2
™
valve and the brake
antilock
chamber for proper operation. If an incomplete release
is noted at all wheels, inspect for a kinked or obstructed
air line leading to or from the AR-2™ valve.
4. Check the AR-2™ valve’s differential pressure by applying
10 psi to the service port and noting the pressure
registered at the delivery port. Subtract delivery port
pressure from the 10 psi service pressure to obtain the
differential. Compare the measured differential with the
pressure specified for the AR-2™ valve part number.
NOTE: For AR-2™ valves not incorporating a relay piston
return spring the measured differential should be
approximately 4 psi. When a spring is in use, the
differential will be higher .
5. Make and hold a full (100 psi or greater) brake application
and note that full pressure is delivered to the brake
chambers.
6. Activate the dash mounted trailer supply valve for bobtail
tractor operation. Then make a slow brake application,
increasing the pressure at the AR-2™ valve service port
to 20 psi while watching the reaction at the delivery port
gauge. Note that delivery pressure rises to approximately
5 to 10 psi and remains constant while service pressure
continues to rise to 20 psi. Release the application.
7. Make another brake application and slowly increase
the pressure at the AR-2™ valve service port to between
60 and 70 psi while observing the gauge installed at the
delivery port. Note that when service port pressure rises
to between 20 and 30 psi, delivery pressure begins to
rise above the initial pressure noted in step 6. The rise
of delivery pressure should be at a proportioned rate of
approximately 3 to 1. For example: Each 3 psi increase
at the service port results in a delivery pressure increase
of 1 psi. At 70 psi service port pressure, brake chamber
pressure should be 15 to 25 psi.
8. Make a full brake application and note that both test
gauges register the same pressure. IMPORTANT: If
during testing the service port pressure is SLOWLY
increased from approximately 70 psi to a full (100 psi
or greater) brake application, the AR-2™ valve MA Y begin
to cycle between an apply and exhaust mode. This
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™
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DASH CONTROL VALVES
TRACTOR
PROTECTION
BRAKE VALVE
FIGURE 9 - TYPICAL CR-16
™
AIR BRAKE SYSTEM
condition is normal while the AR-2™ valve is transitioning
from the proportioning mode to the full delivery mode
and will only occur if the service application is SLOWLY
increased as described. Cycling will not occur or can be
stopped by increasing or decreasing service port
pressure.
9. Remove the test gauges from the AR-2™ valve.
10.If the AR-2™ valve fails to perform as described it should
be replaced or repaired using genuine Bendix
replacement parts or kits.
LEAKAGE TESTS
1. Build the air system pressure to governor cut-out. With
the dash mounted trailer supply valve activated for
tractor/trailer operation, apply a soap solution to both
exhaust ports (one in cover and one in body). The
leakage noted should not exceed a 1” bubble in less
than 3 seconds at either exhaust port.
2. Make and hold a full brake application and apply a soap
solution to both exhaust ports and around the cover
where it joins the body. The leakage noted should not
exceed a 1” bubble in less than 3 seconds at any exhaust
port with no leakage detected between the cover and
body.
™
M-21
MODULATORS
™
WITH
AR-2
CONTROLLER
V AL VE REMOVAL
1. Park the vehicle on a level surface and block the wheels
and/or hold the vehicle by means other than the air
brakes.
2. Drain the air pressure from all vehicle reservoirs.
3. Identify, mark or label all air lines and wiring cables and
their respective connections on the valve or antilock
controller to facilitate ease of installation.
4. Disconnect all air lines and wiring.
5. Remove the AR-2™ valve and controller assembly from
the vehicle.
V ALVE INSTALLATION
1. Install all air line fittings and plugs making certain thread
sealing material does not enter the valve.
2. Install the assembled valve on the vehicle.
3. Reconnect all air lines and wiring cables to the valve
and controller assembly using the identification made
during V AL VE REMOVAL step 3.
4. After installing the valve and controller assembly , test all
air fittings for excessive leakage and tighten as needed.
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1
20
22
2
24
26
30
28
21
23
5
6
3
7
32
34
25
36
27
29
31
33
35
8
4
37
38
39
19
18
40
17
9
16
15
14
13
12
11
10
FIGURE 10 - AR-2
™
ANTILOCK RELAY VAL VE
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DISASSEMBLY
GENERAL
The following disassembly and assembly procedure is
presented for reference purposes only and presupposes
that the appropriate maintenance kit is on hand at the time
of disassembly. The instructions provided with the
maintenance kit should always be used in lieu of those
presented here. Refer to figure 10 throughout the disassembly
and assembly procedure. CAUTION: The AR-2™ valve may
be lightly clamped in a bench vise during disassembly,
however, over clamping will cause damage to the valve and
result in leakage and/or malfunction. If a vise is to be used,
position the valve so that the jaws bear on the supply ports
on opposing sides of the valve’s body .
1. Remove all air fittings and plugs from the AR-2™ valve.
2. Mark the relationship of the antilock electronic controller
(2) and valve cover (4) to the body (9). Note the position
of the mounting bracket (6) and mark the relationship of
the bracket to the valve body (9), cover (4), and antilock
controller (2). Remove and retain the four cap screws
and lock washers (1) that secure the controller to the
cover (4), then carefully remove the electronic controller
without damaging its gasket (3).
3. While holding the exhaust cover (11), remove the retaining
ring (10) that secures it to the body (9).
4. Remove the exhaust cover (1 1) along with both o-rings
(12 & 13).
5. Remove the valve spring (14), valve retainer (15), and
the valve assembly (16) from the body (9).
6. Remove and retain the two cap screws and lock washers
(5) that secure the bracket (6) to the cover (4). Remove
and retain the two bolts with lock washers (7), and nuts
(8) that secure the cover (4) and mounting bracket to
the valve body (9). Then remove the remaining two cap
screws (7) that secure the cover (4) to the body (9).
7. Separate the cover (4) and mounting bracket (6) from
the body (9), then remove the large and small sealing
rings (19 & 40).
8. Remove and retain the relay piston (17) and relay piston
spring (if present) from the body (9). NOTE: The relay
piston spring is not used in all AR-2™ valves.
9. Remove the o-ring (18) from the relay piston (17).
10.Remove the retaining ring (20) from the cover (4), then
remove the exhaust piston (21).
1 1. Remove the exhaust piston o-ring (22).
12.Remove the service piston (23) from the cover (4).
13.Remove the spring (24) and spring cage (25) from the
cover (4).
14.Remove the blend back piston (26) from the valve cover
(4), then remove both o-rings (27 & 28).
15. Remove the proportioning piston (30) from the valve cover
(4), then remove both o-rings (29 & 31).
16.While holding the inlet valve seat (34) in place, remove
the retaining ring (36) from the proportioning piston (30).
17.Remove the inlet valve seat (34), the inlet valve (33),
and the valve spring (32) from the proportioning piston
(30), then remove the o-ring (35) from the valve seat (34).
18. Remove the exhaust diaphragm screw (37), washer (38)
and exhaust diaphragm (39) from the cover (4).
CLEANING & INSPECTION
1. Using mineral spirits or an equivalent solvent, clean and
thoroughly dry all metal parts.
2. Inspect the interior and exterior of all metal parts that
will be reused for severe corrosion, pitting and cracks.
Superficial corrosion and/or pitting on the exterior
portion of the body (9) and cover (4) is acceptable.
Replace the entire valve if the interior of the body or
cover exhibit signs of corrosion or pitting.
3. Inspect the bores of both the body (9) and cover (4) for
deep scuffing or gouges. Replace the entire valve if
either are found.
4. Make certain all air channels and exhaust passages in
the valve cover (4) are clear and free of obstruction.
5. Inspect the pipe threads in the body (9). Make certain
they are clean and free of thread sealant.
6. Wash all non-metallic components in a soap and water
solution making certain to rinse and dry thoroughly.
Inspect each non-metallic component for cracks, wear
or distortion. Replace the entire valve if these conditions
are found.
7. If the valve was equipped with a relay piston spring,
inspect it for signs of corrosion, pitting and cracks.
Replace as necessary .
8. Inspect all air line fittings for corrosion and replace as
necessary . Make certain to remove all old thread sealant
before reuse.
ASSEMBLY
1. Prior to assembly, lubricate all o-rings, seals, and pistons,
as well as body and cover bores, using the lubricant
provided with the Bendix maintenance kit.
2. Install the o-ring (35) on the inlet valve seat (34).
3. Insert the inlet and exhaust valve spring (32), LARGE
END FIRST , into the proportioning piston (30).
4. Install the inlet and exhaust valve (33) inside the inlet
valve seat (34) making certain that the four tabs are
within the bore of the seat.
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5. Carefully insert the assembled valve (33) and seat (34)
into the proportioning piston (30), making certain that
the coils of the valve spring (32) rest on the four tabs of
the valve (33). While holding the seat (34) in place, install
the retaining ring (36) to secure it in the piston (30).
Make certain the retaining ring is fully seated in its
groove.
6. Install both the large and small diameter o-rings (31 &
29) on the proportioning piston (30).
7. Install both the large and small diameter o-rings (27 &
28) on the blend back piston (26), then insert the small
diameter of the proportioning piston (30) into the small
diameter end of the blend back piston (26).
8. Carefully insert the assembled proportioning and blend
back pistons (30 & 26) into the cover (4).
9. Install the spring cage (25) in the blend back piston (26)
so that it’s flat side rests against the blend back piston.
10.Install the spring (24) in the cage (25) so that its coils
are within the I.D. of the cage.
1 1. Insert the service piston (23) in the cover (4) so that the
coils of the spring (24) are contained within the piston
and the six protruding posts of the piston are visible
after the piston is in the cover .
12.Install the o-ring (22) on the exhaust piston (21) then
install the exhaust piston (21) in the cover (4). Refer to
the figure and make certain that the exhaust piston (21)
is installed with its concave surface away from the
service piston (23).
14.While holding the exhaust piston (21) in the cover (4),
install the retaining ring (20), making certain it is fully
seated in its groove.
15.Install the exhaust diaphragm (39) using its screw (37)
and washer (38) to retain it. Torque the screw to 8-15
pound inches.
16.Install the valve retainer (15) on the inlet and exhaust
valve (16) so that the flange of the retainer (15)
surrounds the rubber portion of the valve. Install the
inlet and exhaust valve in the body (9).
17.Install the inlet and exhaust valve return spring (14) in
the body (9).
18.Install the large and small diameter o-rings (13 & 12) in
the cover (1 1), then install the exhaust cover in the body
(9) taking care not to damage the o-rings. Hold the
exhaust cover in place.
19. While depressing the exhaust cover (11), install the
retaining ring (10) in the body (9). Make certain the
retainer (10) is fully seated in its groove in the body.
20. If the AR-2™ valve was equipped with a relay piston return
spring, install the spring in the body , large diameter first.
O-RING IDENTIFICATION CHART
O.D.
W
I.D.
KEY NO. I.D. O.D. W
12 .862" 1.068" .103"
13 1.424" 1.630" .103"
19 3.487" 3.693" .103"
18 3.234" 3.512" .139"
22 1.356" 1.496" .070"
27 1.112" 1.318" .103"
28 .737" .943" .103"
29 .412" .552" .070"
31 .739" .879" .070"
35 .489" .629" .070"
21.Using lubricant to hold them in place, install the large
diameter sealing ring (19) on the cover (4) and the
small diameter sealing ring (40) on the body (9).
22. Install the o-ring (18) on the relay piston (17), then install
the piston in the body (9).
23. After noting the relationship marks made prior to
disassembly , install the cover (4) on the body (9). Secure
the cover to the body using the two shortest cap screws
and lock washers (7). Make certain the sealing rings
(19 & 40) remain in place. Torque the cap screws to
120-150 pound inches.
24.Secure the mounting bracket (6) to the cover (4) using
the cap screws and lock washers (5), and torque the
cap screws to 180-220 pound inches. Then secure the
mounting bracket (6) to the body (9) and cover (4) using
the two longest cap screws and lock washers (7) and
nuts (8) and torque the cap screws to 120-150 pound
inches.
25.Install all air line fittings and plugs making certain thread
sealing material does not enter the valve.
26.Install the AR-2™ valve on the vehicle and perform the
Operation and Leakage T ests before returning the vehicle
to service.
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BW1672 © 2004 Bendix Commercial Vehicle Systems LLC All rights reserved. 6/2004 Printed in U.S.A.
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