Bleeding The Hydraulic System; Removal Of Hand Pump; Disassembly Of Hand Pump; Cleaning, Inspection And Repair Of Hand Pump - Piper Navajo Chieftain PA-31-350 Service Manual

NAVAJO CHIEFTAIN SERVICE MANUAL
6-102. FILLING HYDRAULIC RESERVOIR. (Refer to Section II, Servicing Hydraulic Reservoir.)
6-103. BLEEDING THE HYDRAULIC SYSTEM.
a.
Jack the airplane as described in Section II.
b.
Ascertain that the reservoir is full.
c.
Connect a hydraulic test unit to the airplane as described in Paragraph 6-8.
d.
Cycle the landing gear system through several cycles.
e.
Check that hydraulic reservoir is full.
f.
Disconnect the hydraulic test unit as described in Paragraph 6-17.
g.
Ascertain that the landing gear selector handle is in the down neutral position, and that the
landing gear is down and locked.
h. Remove the airplane from jacks.
6-104. HAND PUMP (EMERGENCY) (Ozone).
6-105. REMOVAL OF HAND PUMP.
a.
Remove the pump access panel located between the pilot's and copilot's seats.
b.
Disconnect the hydraulic pressure and suction lines from the forward end of the pump.
c.
Remove the pump from its mounting bracket by removing attachment bolts.
d.
Remove the pump from the airplane.
e.
Cover the pressure and suction lines to prevent contamination.
6-106. DISASSEMBLY OF HAND PUMP. (Refer to Figure 6-20.)
a.
To remove the plunger (13) and component parts, remove pin (22) and Allen screws (19)
allowing the bracket (18) to separate from the pump body (6).
b.
Pull the plunger assembly from the pump body.
c.
Slide the scraper (17) and packing gland (15) from the plunger (13).
d.
To remove the check ball assembly from the plunger, remove the snap ring (7) in the end of the
plunger and with a low charge of air injected into the hole in the side of the plunger, blow the check ball
(10) and seat (9) from the plunger. Remove the spring ( 1).
e.
To remove the check ball assembly located in the suction port, reach into the port with a pair of
long snap ring pliers and remove the snap ring (1). With a low charge of air injected into the interior of the
pump body, blow the seat (3) and check ball from the suction port. Remove the spring (5).
6-107. CLEANING. INSPECTION AND REPAIR OF HAND PUMP.
a.
Clean the pump parts with a suitable solvent and dry thoroughly.
b.
Inspect the pump body for scratches, burrs. etc., that could damage O-rings and threaded areas
for damage.
c.
Inspect pump handle assembly for signs of corrosion at the attachment point. If corrosion is
evidenced or present. replace the handle assembly.
d.
Inspect the plunger for enlarged pin hole, surface area for scratches. burrs. etc., that could damage
O-rings.
e.
Inspect check balls and seats for damaged seating areas and corrosion.
f.
Check general condition of remaining parts.
g.
Repairs to the pump are limited to polishing out small scratches, burrs, etc., replacing O-rings and
worn or damaged parts.
Revised: 3/5/84
HYDRAULIC SYSTEM
2C12