Piper Navajo PA-31 Service Manual page 361

PIPER NAVAJO SERVICE MANUAL
i. Attach the bracket (21) to the pump body (6) with the four screws (25). Torque to 70
inch-pounds.
j. Position link (23) and install quick click pin (14).
k. Lubricate "O" ring (2) and install on seat (3).
l. Install spring (5), ball (4) and lubricated seat (3) into the suction port of the pump body (6) and
secure with snap ring (1).
6-121. INSTALLATION OF HAND PUMP.
a. Position the hand pump on its mounting bracket and secure with bolts.
b.
Connect the hydraulic pressure and suction lines to the forward end of the pump.
c. Bleed the hand pump as described in Paragraph 6-122 and test the hand pump as described in
Paragraph 6-123.
d.
Install access panel.
e. Ascertain that the reservoir is filled with hydraulic fluid.
6-122. BLEEDING HAND PUMP. The hand pump may be purged by operating the pump until all air has
been expelled from the pump. This will usually require approximately 15 cycles of the pump.
6-123. HAND PUMP TEST.
a.
Ascertain that the reservoir is filled with hydraulic fluid.
b. Remove cap from door-open port and operate emergency hand pump until fluid flows from port
with no evidence of air in the system. Replenish reservoir with clean hydraulic fluid as necessary to
maintain fluid level.
c. After pump is primed and bled of all air, remove fitting and install 2100 PSI gauge at door-open
port.
port. d. Operate emergency hand pump very slowly until pressure on gauge stops increasing, indicating
that the hand pump relief valve has opened.
CAUTION
It is very important that the hand pump be operated very slowly
as pressure is being increased to bleed the hand pump relief valve.
If the hand pump is operated rapidly, damage to the valve can
occur as air permits parts to "slam" against each other.
Maximum indication of the gauge should be as indicated in Table VI-II. During the pumping
operation, the emergency hand pump should not feel spongy in either the up or down stroke.
e. Crack gauge in door-open port to release pressure; remove gauge; reinstall and cap door-open
fitting and drain fluid from reservoir.
6-124. GEAR ACTUATING CYLINDERS (OZONE).
6-125. REMOVAL OF GEAR ACTUATING CYLINDERS.
a. Place the airplane on jacks. (Refer to Jacking, Section II.)
b. Disconnect the hydraulic lines from the actuating cylinder and cover the open line ends to
prevent contamination.
c.
Disconnect the cylinder operating rod end from the link assembly.
d. Disconnect the attachment end of the cylinder by removing the bolt that secures the cylinder and
nose gear uplock rod or the main gear uplock crank assembly.
e.
Remove the cylinder from the wheel well.
Reissued: 10/12/79
HYDRAULIC SYSTEM
2D7