Bendix Commercial Vehicle Systems PP-3 TRAILER SUPPLY VALVE 3/04 - Manual (Page 3)

3
DISASSEMBLY
PP-3 ™ PUSH-PULL VALVE
1. Button pin (1) Figure 3, button (2) and mounting nut (3)
are normally removed when valve is removed from
vehicle.
2. Remove two lower body cap screws (4) and lock washers,
then lower body (5) with cover (6).
3. Remove cover with tripper piston (7) from lower body.
4. Remove tripper piston and spring (8) from cover.
5. Remove tripper piston and cover seal o-rings (9 & 10).
6. Insert rod or punch in upper plunger pin hole and hold
plunger (11) from turning while inlet and exhaust valve
nut is removed.
7. Remove washer (13) and valve (14).
8. Pull plunger from upper body.
9. Remove plunger spring (15) and o-ring (16).
10. Remove upper body seal ring (17). Do not remove plugs
from ports marked “Del” in upper body.
CLEANING AND INSPECTION OF PARTS
Wash all metal parts in mineral spirits and then dry.
In particular, make sure supply port in PP-3 ™ valve upper
body, tripper by-pass slot, and tripper exhaust port in cover
are thoroughly cleaned and unrestricted.
Inspect all parts for excessive wear or deterioration.
Inspect seats in upper and lower body for nicks and burrs.
Redress seats if damaged.
Inspect plunger and tripper piston bores in bodies and cover
for deep scratches or nicks. They should be smooth and
clean.
Check springs for distortion, corrosion, and cracks.
Replace all parts not considered serviceable during these
inspections, especially o-rings and valves.
ASSEMBLY
Prior to assembly, lubricate o-rings and bearing surfaces
with silicone lubricant Bendix Pc. No. 291126.
1. Install plunger o-ring (16).
2. Position plunger spring (15) in upper body, then press
plunger (11) down inside spring in the body.
3. Place inlet and exhaust valve (14), then washer (13),
over threaded, protruding end of plunger.
4. Install and tighten self-locking nut (12). Torque on the
nut should be 30 to 40 inch pounds.
5. Place upper and lower body seal o-ring (17) in place.
6. Install tripper piston o-ring (9).
7. Position cover o-ring seal (10) on cover.
8. Position tripper spring (8) in cover (6) then press tripper
piston (7) down over spring and into the cover bore.
9. Place cover with tripper installed into lower body.
10. Fasten lower body and cover assembly to upper
assembly with cap screws (4) and lockwashers. Tighten
cap screws evenly and securely.
TESTING REBUILT PP-3 ™ VALVE
Perform operating and leakage checks as outlined in previous
section.
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.
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.
FIGURE 3 - PP-3 ™ CONTROL VALVE
SPIROL PIN (1)
EXHAUST
PORT
PLUNGER (11)
TRIPPER
SPRING (8)
BUTTON (2)
SUPPLY
PORT
INLET AND
EXHAUST
VALVE (14)
SPRING (15) NUT (3)
O-RING (16)
PIPE PLUG
SEAL (17)
INLET AND
EXHAUST
VALVE NUT
(12)
LOWER BODY
(5)
O-RING (9)
CAP SCREW
(4)
TRIPPER
EXHAUST
COVER (6)
TRIPPER
PISTON (7)
DELIVERY
PORT
WASHER (13)
O-RING (10)