Assembly Of Hand Pump Check Valve; Assembly Of Priority Valve; Assembly Of Main Relief Valve; Assembly Of Hand Pump Relief Valve - Piper Navajo Chieftain PA-31-350 Service Manual

NAVAJO CHIEFTAIN SERVICE MANUAL
6-35. ASSEMBLY OF STANDPIPE AND FILTER. (Refer to Figure 6-6.)
a. If the standpipe and filter assembly (68) was removed, press into the body until the standpipe
bottoms.
b. Replace the vent filter (83) and the snap ring (82).
6-36. ASSEMBLY OF HAND PUMP CHECK VALVE. (Refer to Figure 6-6.)
a. With the pressure port up, drop the spring (33) into the port.
b. Drop in the plunger (32), making sure that the small end of the plunger goes into the spring.
Check freeness of the plunger in the body by depressing the plunger against the spring. Use a small wooden
dowel or plastic rod to depress the plunger when checking for freedom of movement. The plunger must
move freely in the body bore.
c. Lubricate and install the O-rings (30 and 31) on the flange of the fitting (29) and at the end of
the fitting. Lubricate the threads, insert the fitting. Start threads and tighten securely.
6-37. ASSEMBLY OF PRIORITY VALVE. (Refer to Figure 66.)
a.
Lubricate and install the O-ring (19) on the poppet (18) and insert the poppet in the body
through the reservoir. Push the poppet down firmly. Either surface may be used as the seating surface.
b. Inspect the poppet seat for a sharp seating edge. Lap as necessary to obtain a sharp seating edge.
Lubricate and install the O-ring (17) on the poppet seat (16).
c. Install the poppet seat in the body through the reservoir, with the sharp seating edge toward the
poppet. Push the poppet seat (16) down firmly against the poppet (18).
d. Lubricate and install the O-ring (15) on the retainer (priority) assembly (14), lubricate the
retainer threads, and install the retainer. Tighten securely.
e.
Turn the power pack upside down, lubricate the spring (37) and button (38) and install the body
(48). Apply lubricant to hold the button in the spring and install with the button in the hole first.
f. Lubricate the threads on the retainer (35) (adjusting plug) and install. This plug provides
adjustment for the priority valve. Install flush at this time.
6-38. ASSEMBLY OF MAIN RELIEF VALVE. (Refer to Figure 6-6.)
a. Inspect the poppet (9) and poppet seat (10) for pitting or scoring. Since they are matched parts,
if either or both are pitted or scored, replace as an assembly only.
b. Lubricate and install the O-ring (12) and back-up ring (11) on the poppet seat (10), insert the
poppet (9) in the seat (10),
and install the assembly in the body.
c.
Lubricate the ball (8), buttons (5 and 7), and spring (6). Install with the ball entering the hole
first. Be sure that the ball enters the cavity at the top of the poppet.
d.
Lubricate the threads on the retainer (4) and install over the button (5) and spring (6). Tighten
securely.
e. Lubricate the threads of the adjusting screw (3) and install at the top of the retainer (4). Turn the
adjusting screw full down to lock the main relief valve closed, but do not tighten the locknut (2). This is
done so that the hand pump relief valve which opens at a higher pressure, can be adjusted before the main
relief valve is adjusted.
6-39. ASSEMBLY OF HAND PUMP RELIEF VALVE. (Refer to Figure 6-6.)
a.
Lubricate and install the O-ring (63) in the body (48). Make sure the O-ring seats properly.
b. Inspect the seating surface of the seat (62). It should have a very sharp edge. The seat may be
lapped to obtain a sharp edge.
c. Install the seat (62) in the body, with the sharp edge of the seating surface up.
d. Install the poppet (61) and spring (60) together, and insert in the body with the ball end toward
the seat.
Reissued: 9/23/80
HYDRAULIC SYSTEM
2B9