BENDIX R-8P User manual

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BENDIX®R-8P™PILOT RELAY VALVE MAINTENANCE KIT
Figure 1 – Bendix®R-8P™Pilot Relay Valve Maintenance Kit Contents
1
Spring
Piston
2
3
4
Exhaust
Cover
5Screw Washer
Valve Cover
Valve Body
Piston Orices
Service
(Control)
Port
Delivery
Ports
Exhaust
Supply
Kit Contents
Item No. Description Qty.
1 O-Ring 1
2 O-Ring 1
3 Sealing Ring 1
4 Inlet / Exhaust Assembly 1
5 Exhaust Diaphragm 1
6 Tube of Lubricant 1
Bendix®R-8P™Pilot
Relay Valve
2
3
4
51
6

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GENERAL SAFETY GUIDELINES
WARNING! PLEASE READ AND FOLLOW THESE INSTRUCTIONS
TO AVOID PERSONAL INJURY OR DEATH:
When working on or around a vehicle, the following guidelines should be observed AT ALL TIMES:
▲Park the vehicle on a level surface, apply the
parking brakes and always block the wheels.
Always wear personal protection equipment.
▲Stop the engine and remove the 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.
▲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.
▲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 a
Bendix®AD-IS®air dryer system, a Bendix®DRM™
dryer reservoir module, or a Bendix® AD-9si®air
dryer, be sure to drain the purge reservoir.
▲Following the vehicle manufacturer’s
recommended procedures, deactivate the
electrical system in a manner that safely removes
all electrical power from the vehicle.
▲Never exceed manufacturer’s recommended
pressures.
▲Never connect or disconnect a hose or line
containing pressure; it may whip and/or cause
hazardous airborne dust and dirt particles. Wear
eye protection. Slowly open connections with
care, and verify that no pressure is present. Never
remove a component or plug unless you are
certain all system pressure has been depleted.
▲Use only genuine Bendix®brand replacement
parts, components and kits. Replacement
hardware, tubing, hose, fi ttings, wiring, etc. must
be of equivalent size, type and strength as original
equipment and be designed specifi cally for such
applications and systems.
▲Components with stripped threads or damaged
parts should be replaced rather than repaired.
Do not attempt repairs requiring machining or
welding unless specifi cally stated and approved
by the vehicle and component manufacturer.
▲Prior to returning the vehicle to service, make
certain all components and systems are restored
to their proper operating condition.
▲For vehicles with Automatic Traction Control
(ATC), the ATC function must be disabled (ATC
indicator lamp should be ON) prior to performing
any vehicle maintenance where one or more
wheels on a drive axle are lifted off the ground
and moving.
▲The power MUST be temporarily disconnected
from the radar sensor whenever any tests USING
A DYNAMOMETER are conducted on a vehicle
equipped with a Bendix® Wingman®system.
▲You should consult the vehicle manufacturer's operating and service manuals, and any related literature,
in conjunction with the Guidelines above.

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REMOVAL
1. Block or hold the vehicle by means other than the
brakes.
2. Drain all air brake system reservoirs.
3. Identify, mark, and disconnect all air lines from the
Bendix®R-8P™pilot relay valve.
4. Remove the R-8P valve from its mount on the vehicle.
DISASSEMBLY
1. Note and mark the position of the valve cover to the
body.
2. Remove the four 5/16"-18 hex screws and separate the
cover from the body.
3. Remove and discard the sealing ring (3) from the body.
4. Remove the piston and spring from the cover and retain
all parts.
5. Remove and discard the o-ring (2) from the piston.
6. Remove the screw, washer, and diaphragm (5) from
the exhaust cover. Discard the diaphragm (5).
7. Remove the four 10-24 screws which secure the
exhaust cover to the body.
8. Remove and discard the inlet exhaust assembly (4)
from the body.
9. Clean all remaining parts in a cleaning solvent
equivalent to mineral spirits. Make certain all surfaces,
bores, and passages are clean and dry.
ASSEMBLY
NOTE: Make certain both piston orices are open and not
clogged. Grease all o-rings, o-ring grooves and bores with
the lubricant (6) provided in this kit.
1. Install diaphragm (5) and diaphragm washer and secure
with screw. Torque screw to 15-25 in-lbs.
2. Install the inlet and exhaust valve assembly (4) in the
valve body. Position exhaust cover assembly so that all
holes are properly aligned and secure with four 10-24
screws. Torque screws to 20-30 in-lbs.
3. Install the sealing ring (3) in the valve body.
4. Install o-rings (1) & (2) on the piston.
5. Install the spring in the valve cover so that the large
diameter end of the spring will rest on the piston.
6. Install the piston (with its o-rings installed) in the valve
cover. NOTE: Make certain the spring is centered and
not binding.
7. Install the valve cover on the valve body in the same
position as marked in Step 1 of "Disassembly". Secure
the cover to the body using the four 5/16" hex head cap
screws. Torque to 120-150 in-lbs.
INSTALLATION
1. Mount the R-8P on the vehicle.
2. Connect the air lines to the R-8P valve using identication
made during Step 3 of "Removal" instructions.
3. Perform "Operating and Leakage Checks" before
placing the vehicle into service.
OPERATING AND LEAKAGE CHECKS
1. Block the wheels and fully charge the air system. Adjust
the brakes.
2. Apply and release the service brakes several times
and check for prompt response of the brakes at all
appropriate wheels.
3. With the air system fully charged, apply a soap solution
to the exhaust of the R-8P valve. Leakage of a 1" bubble
in 5 seconds is permissible.
4. Make and hold a full brake application and again apply
a soap solution to the R-8P exhaust. Leakage of a
1" bubble in three seconds is permissible.
5. With the brakes still applied, apply a soap solution
around the valve where the cover meets the body. No
leakage at this point is permitted.
If the valve is unable to pass these operating and leakage
checks, it is recommended that it be exchanged for a
genuine Bendix®remanufactured exchange unit.

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S-0850 Rev. 002 © 2019 Bendix Commercial Vehicle Systems LLC, a member of the Knorr-Bremse Group • 03/19 • All Rights Reserved
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