Hydraulic Power Pack - Ozone; Removal Of Power Pack; Disassembly Of Power Pack; Power Pack Installation - Piper Navajo Chieftain PA-31-350 Service Manual

NAVAJO CHIEFTAIN SERVICE MANUAL
6-20. HYDRAULIC POWER PACK (OZONE).
6-21. REMOVAL OF POWER PACK. (Refer to Figure 6-3.)
a. Remove the access panels to the power pack on both sides of the fuselage nose section at station
46.0. Also remove the upper access panel on the aft bulkhead of the forward baggage compartment.
NOTE
All disconnect and removal work can be accomplished from the
upper baggage compartment access or right access panel
b. Drain the power pack by removing the drain cap from the end of the drain on the right side of
the fuselage nose section at station 48.0. Place a suitable container under the drain to catch the fluid.
Replace the cap after the reservoir is empty.
c. Disconnect the electrical connector (8) located at the forward end of the power pack (4).
d. Disconnect the vent line (3) from the power pack cap.
e. Disconnect the gear selector control from the power pack control arm on the right side of the
power pack.
f. Disconnect the various hydraulic lines from the power pack. Cap the open lines to prevent
contamination.
g. Remove the attachment bolts (7) which secure the power pack to the mounting brackets (6).
h. Move the power pack forward and out through the baggage compartment.
6-22. DISASSEMBLY OF POWER PACK. (Refer to Figure 6-6.) After the power pack has been removed
from the airplane and all ports are capped or plugged, spray with cleaning solvent (Federal Specification
P-S-661, or equivalent) to remove all accumulated dust or dirt. Dry with filtered compressed air. To
disassemble the unit, proceed as follows:
a. Remove retaining nut (86), O-ring (87) and reservoir cover (56). Cover is a snug fit on reservoir.
Use a soft mallet and tap cover lightly to remove. Remove large O-ring (85).
b. Remove sight gauge (20).
c. Remove spacer (84) from cover center stud (21), cut safety wire and remove baffle (81) from
reservoir. Drain remaining hydraulic fluid from reservoir.
d. Remove the reservoir cover center stud (21). This stud may be removed by using a double
locknut at the top of the stud. Use care to prevent damage to the stud threads.
e. Turn the power pack upside down so that the top of the reservoir serves as a support base.
NOTE
All electrical wires are coded with color stripes. Disregard color of
wire terminals or plastic sleeving. If color codes are matched when
wires are reinstalled, the wires will be connected correctly.
f. Cut safety wire and remove screws attaching landing gear up-down switch and bracket. Retain
washers between bracket and power pack. (Refer to Figure 6-3.)
g. Turn power pack over and cut safety wire at time-delay valve.
h. Remove time-delay valve ball, spring, spacer, and spring by removing time-delay retainer.
Reissued: 9/23/80 HYDRAULIC SYSTEM
2B4