Disassembly Of Hand Pump Relief Valvfe; Disassembly Of Main Relief Valve; Disassembly Of Priority Valve; Disassembly Of Standpipe And Filter - Piper Navajo Chieftain PA-31-350 Service Manual

NAVAJO CHIEFTAIN SERVICE MANUAL
NOTE
Do not bend the selector spool. Pull straight out. The landing gear
selector spool (26), time-delay plunger (3), and manifold (24) are
matched, lapped parts. If it is necessary to replace any one of
these three parts, replace them as an assembly only.
f.
Remove the landing gear handle-release retainer (17) (adjusting plug), nut (31), spring (18), screw
(32), and poppet (20) from the manifold. The end of the poppet has a ball which should remain in the
poppet. If it doesn't, remove the ball from the manifold.
g.
Remove the caps from the fittings and wash the manifold in cleaning solvent (Federal
Specification P S-661 or equivalent) and dry with filtered compressed air. Be sure internal passages are
clean, then reinstall caps on fittings.
6-24. DISASSEMBLY OF HAND PUMP SUCTION SCREEN. (Refer to Figure 6-6.)
a.
Remove the suction screen (67) by removing the snap ring (65) and spacer (66).
6-25. DISASSEMBLY OF HAND PUMP RELIEF VALVE. (Refer to Figure 6-6.)
a.
Remove the adjusting plug (58) at the top of the hand pump relief valve.
b.
Remove the hand pump relief valve retainer (59) by unscrewing from the body.
c.
Remove the spring (60) and poppet (61) from the body.
d.
Use a brass hook to remove the seat (62) from the body. Use care to prevent scoring the bore.
e.
Remove the O-ring (63) from the bottom of the cavity.
6-26. DISASSEMBLY OF MAIN RELIEF VALVE. (Refer to Figure 6-6.)
a.
Loosen the locknut (2) at the top of the main relief valve.
b.
Remove the adjusting screw (3) and locknut (2) from the top of the relief valve.
c. Unscrew the retainer (4).
d.
Remove the two buttons (5 and 7), spring (6) and ball (8).
e.
Remove the poppet (9) from the poppet seat (10) by lifting out of the poppet assembly. The
poppet and poppet seat are matched parts.
f.
Using a brass hook not over .125 inch long, pull the poppet seat up out of the body. Hook
through holes in the side of the seat and use care not to damage the bore in the body.
6-27. DISASSEMBLY OF PRIORITY VALVE. (Refer to Figure 6-6.)
a.
Remove the priority retainer (14) from the reservoir.
b.
Turn the power pack upside down and remove the retainer (35) (adjusting plug), spring (37) and
button (38) from the bottom of the power pack.
c.
While the power pack is upside down, push the poppet (18) and poppet seat (16) into the
reservoir, using a punch of .125 inch maximum diameter. Make sure that the face of the punch is square
and flat.
6-28. DISASSEMBLY OF HAND PUMP CHECK VALVE. (Refer to Figure 6-6.)
a.
Remove the system pressure port fitting (29). The spring (33) and plunger (32) should fall out of
the power pack after the O-ring (31) is removed. Use hook, if necessary to remove the O-ring.
6-29. DISASSEMBLY OF STANDPIPE AND FILTER. (Refer to Figure 6-6.)
a.
The standpipe and filter assembly (68) should not be removed unless it is damaged, since it is a
press fit in the reservoir.
b.
Remove the vent filter (83) by removing the snap ring (82).
Reissued: 9/23/80
HYDRAULIC SYSTEM
2B6