Bendix Commercial Vehicle Systems R-8 RELAY VALVE - Manual (Page 3)

3
(NOTE: The standard R-8 ™ valve does not employ a piston
return spring. However, it is optionally used in some
values.)
3. Remove the sealing ring from the groove in the body.
4. Remove the relay piston and o-ring from the cover.
5. Remove the service port cap nut from the cover and
remove the cap nut o-ring from the cap nut.
6. Remove the quick release diaphragm from the service
port.
7. If the exhaust port of the quick release is protected with
a cover, remove the cover by removal of the #10-24 phillips
screw.
8. Remove the #10-24 phillips screw that secure the
exhaust diaphragm and washer to the exhaust cover.
9. Remove the four #10-24 phillips head screws that secure
the exhaust cover to the body.
10. Remove the inlet/exhaust valve insert from the body.
(NOTE: If a new inlet/exhaust value insert is to be installed,
omit step 11.)
11. Disassemble the insert by removing the retaining ring
and separating; the special washer, o-ring retainer and
o-rings, the valve spring, valve retainer and the inlet
and exhaust valve.
CLEANING AND INSPECTION
1. Wash all metal parts in mineral spirits and dry them
thoroughly.
(NOTE: When rebuilding the R-8 ™ valve, all springs and all
rubber parts should be replaced.)
2. Inspect all metal parts for deterioration and wear, as
evidenced by scratches, scoring and corrosion.
3. Inspect the exhaust valve seat on the relay piston for
nicks and scratches which could cause excessive
leakage.
4. Inspect the inlet valve seat in the body for scratches
and nicks, which could cause excessive leakage.
5. Inspect the exhaust seat of the quick release diaphragm
in the R-8 ™ valve cover and make sure all internal air
passages in this area are open and clean and free of
nicks and scratches.
6. Replace all parts not considered serviceable during
these inspections and all springs and rubber parts. Use
only genuine Bendix replacement parts which are
available from Bendix outlets.
ASSEMBLY
Prior to reassembling the R-8 ™ relay valve, lubricate all
o-rings, o-ring grooves, piston bores and metal to metal
moving surfaces with Dow Corning Silicone 55-M Pneumatic
Grease (Bendix pc. 291126).
(NOTE: All torques specified in this manual are assembly
torques and can be expected to fall off, after
assembly. Do not retorque after initial assembly
torques fall. To convert inch pounds of torque to foot
pounds of torque, divide inch pounds by 12.
Inch Pounds
12 =Foot Pounds
To convert foot pounds of torque to inch pounds of torque
multiply foot pounds by 12.
Foot pounds x 12 = Inch pounds
For assembly, hand wrenches are recommended.
1. Install the o-ring on the service port cap nut.
2. Place the quick release diaphragm in the R-8
™ valve
cover: be certain it is positioned down between the guide
ribs in the cover. Install the service port cap nut. Torque
to approximately 150 inch pounds.
3. If the quick release exhaust port was protected with an
exhaust cover, install the cover using one of the #10-24
phillips head screws. Torque to approx. 15-25 inch
pounds.
4. Install o-ring on the relay piston and install the piston in
the cover.
(NOTE: If a new inlet/exhaust valve insert is used, omit steps
5-8.)
5. Place the inlet/exhaust valve, rubber side down, on a
clean flat surface. Install the valve retainer then the spring
on the inlet exhaust valve.
6. Install the two o-rings in their appropriate grooves in
the o-ring retainer and place the special washer over
the o-rings.
7. While holding the o-ring retainer and special washer
together, install them over the inlet and exhaust valve,
making sure the inlet valve spring is bearing on the
o-ring retainer
8. Install the retainer ring in the groove around the inlet
and exhaust valve while holding the assembly
compressed.
9. Install the inlet/exhaust valve insert in the body bore.
10. Place the exhaust cover on the body and secure it using
the four #10-24 phillips head screws. Torque the screws
to 20-30 inch pounds.
11. Place the exhaust diaphragm on the exhaust cover and
secure it using the diaphragm washer and the remaining
#10-24 phillips head screw. Torque the screw to
approximately 5-10 inch pounds.
12. Prior to assembling the cover to the body note the mark
made during disassembly to obtain the proper cover
body relationship.