Piper Cherokee LANCE, Service Manual

Page: 216 / 854

PIPER CHEROKEE SIX / LANCE SERVICE MANUAL
VA - HYDRAULIC SYSTEM 07/15/06
1J12
5A-10a. SERVICE REPLACEMENT OILDYNE PUMP (P/N 38998-004).
NOTE: No field repair of Oildyne hydraulic pumps is authorized. Any faulty hydraulic pump must be
replaced; or, returned to Piper, via the local Piper Distributor, for repairs.
a. Servicing Hydraulic Pump/Reservoir
CAUTION: THE PUMP MUST HAVE THE DIPSTICK LOOSENED 1 1/2 TURNS TO
PROPERLY VENT IT.
The fluid level of the reservoir of the combination pump and reservoir should be checked every 50
hours by checking the dipstick indication. Access to the pump is through the access panel in the aft
wall of the baggage compartment.
Should the fluid level be low, add fluid, MIL-H-5606, and return the dipstick. After tightening the
dipstick, loosen it 1 1/2 turns to allow the reservoir to vent.
b. Removal
The hydraulic pump, with reservoir incorporated, is located in the forward section of the
fuselage. Access to the pump is through the access panel in the floor of the forward baggage
compartment. To remove pump:
(1) Disconnect the pump electrical leads from the pump solenoid relays and the ground wire from
the battery shelf.
(2) Disconnect the hydraulic lines from the pump. Cap the line ends to prevent contamination.
(3) Remove pump by removing pump attaching bolts.
(4) Cap or plug all ports.
(5) Clean exterior of pump using a dry cleaning solvent to remove accumulated dirt and dust.
c. Installation (Refer to Figure 5A-5.)
(1) Position assembled pump, bracket, and pump mount on pump deck in airplane.
(2) Secure pump assembly to deck by installing the three AN3-10 bolts with one MS35489-64
washer under each bolt head and three No. 5712-45 (Piper P/N 494 192) washers between
Piper mount assembly and pump deck.
NOTE: Before positioning the complete hydraulic pump assembly on the mounting bracket,
ensure that the cushion pad is secured in place on the reservoir base.
(3) Install the UP and DOWN pressure hydraulic lines to pump mount.
(4) Connect the three knife connectors that attach the black, blue, and green forward and reverse
harness wires.
(5) Check fluid level in pump. Fill per instructions given in Section II.
(6) Install baggage compartment access panel.