BENDIX R-12DC Installation Instructions page 3

5. Remove the relay piston from the valve body and retain
for reuse.
6. Remove and discard the o-ring (6) from the relay
piston.
7. Depress and hold the exhaust cover (12) and remove
and discard the retaining ring (13) from the valve body.
8. Slowly release the holding force on the exhaust cover
assembly (12) to relax the spring.
9. Remove and discard the following parts:
a. Exhaust cover assembly (12)
b. O-rings (10 & 11)
c. Spring (9)
d. Inlet & exhaust valve (7)
e. Valve retainer (8)
CLEANING AND INSPECTION
1. Wash all metal parts in mineral spirits and dry them
thoroughly.
(NOTE: When servicing the Bendix
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 check valve seat in the R-12DC valve cover
and make sure all internal air passages in this area are
open, 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
any authorized Bendix parts outlet.
ASSEMBLY
NOTE: All torques specified in this manual are assembly
torques and can be expected to fall off slightly after
assembly. Do not re-torque after initial assembly torque
fall. For assembly, hand wrenches are recommended.
Prior to assembly, lubricate all o-rings, o-ring bores and any
sliding surface with the lubricant (14) provided.
Wash all remaining parts in mineral spirits and dry
thoroughly. Lightly lubricate all o-rings, o-ring grooves,
body bores and sliding surfaces.
1. Install the o-rings (10 & 11) in the exhaust cover (12).
2. Install the o-ring (6) on the relay piston.
3. Install the sealing o-ring (5) on the valve cover.
4. Install the valve retainer (8) on the inlet and exhaust
valve (7) and insert both in the valve body.
R-12DC
®
replacement parts, available from
®
5. Install the spring (9) in the valve body.
6. Install the exhaust cover assembly (12) in the valve
body. Depress and hold the exhaust cover assembly
in the valve body.
7. Install the retaining ring (13) in the body. Make certain
the retaining ring is completely seated in the groove in
the body.
8. Install the relay piston in the valve body.
9. Install the o-ring (4) on the double check cover. Install
the spring (1), check valve guide (2) and check valve
(3) in the cover. Install the cover and torque the Torx
head screws to 80–100 in-lbs.
10. Referring to the marks made during disassembly, install
the cover.
11. Install the mounting bracket (not shown) on the cover.
12. Install the four cap screws in the cover and torque to
80–100 in-lbs.
INSTALLATION
1. Clean the air lines.
valve,
®
2. Inspect all lines and/or hoses for damage and replace
as necessary.
3. Install the valve and tighten the mounting bolts.
4. Connect the air lines to the valve (plug any unused
ports).
5. Test the valve as outlined in Operational and Leakage
Test.
OPERATIONAL AND LEAKAGE TEST
1. Chock the wheels, fully charge the air brake system,
and adjust the brakes.
2. Make several brake applications and check for prompt
application and release at each wheel.
3. Check for inlet valve and o-ring leakage. Make this
check with the service brakes released. Coat the
exhaust port and the area around the retaining ring with
a soap solution; a one inch bubble in three seconds
leakage is permitted.
4. Check for exhaust valve leakage. Make this check with
the service brakes fully applied. Coat the outside of the
valve where the cover joins the body to check for seal
ring leakage; no leakage is permitted.
If the valves do not function as described above, or if
leakage is excessive, it is recommended that the valves
be replaced with new or remanufactured units or repaired
with genuine Bendix
Bendix parts outlet.
parts, available at any authorized
®
®
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