Testing Door Vent Valve; Assembly Of Power Pack; Testing Reservoir For Leakage; Installation Of Power Pack - Piper Navajo Chieftain PA-31-350 Service Manual

NAVAJO CHIEFTAIN SERVICE MANUAL
6-51. TESTING DOOR VENT VALVE.
a. Remove the cap from the door-open fitting on the Power Pack, and attach the pressure hose from
the hand pump with the 150 psi pressure gauge to the door-open fitting.
b. Check for fluid seepage while slowly applying the stated pressure in Table VI-I.
c. Check to see that the door vent valve shuts off fluid flow when the pressure stated in Table VI-I
is applied. (Slow decrease in pressure from the valve leakage is normal.)
d. Relieve pressure by cracking the hose fitting from the hand pump.
e. Disconnect the test unit and cap all open fittings.
6-52. ASSEMBLY OF POWER PACK. (Refer to Figure 6-6.) To complete the reassembly of the power
pack, proceed as follows:
a.
Install the reservoir cover attaching center stud (21). Install with the longer threaded end down.
and screw in until the stud bottoms in the reservoir.
b. Install the plate (81) and spacer (84) of the center stud. Safety wire the primary relief valve
locknut (2) to the screened standpipe (68).
c. Lubricate and install the O-ring (85) in the groove of the reservoir cover.
d. Position the cover (56) on the reservoir, aligning the index marks on the reservoir and cover. The
vent fitting in the cover points to the left with the power pack in the airplane.
CAUTION
Be sure that the large O-ring is positioned properly in the groove
of the reservoir cover and that the O-ring is not pinched as the
cover is installed.
e. Lubricate and install the O-ring of the cover (87) at the top of the cover and around the center
stud (21).
f. Install the cover retaining nut (86) (cap nut), tighten and safety.
6-53. TESTING RESERVOIR FOR LEAKAGE
a. Remove the drain fitting and attach a test unit and 150 psi gauge to the filler or drain port.
b. Remove the cap from the reservoir vent fitting at the top of the reservoir and operate the test
pump until the reservoir is completely full, as indicated by fluid coming out of the fitting.
c. Cap the reservoir vent fitting.
d. Operate the test hand pump very slowly until the pressure gauge indicates 15 psi maximum.
e. Check for leaks. There should be no external leakage.
f. Crack the vent fitting to release pressure, remove the test equipment, drain the reservoir, and cap
the fittings.
g. The hydraulic power pack is now ready to be installed in the airplane.
6-54. INSTALLATION OF POWER PACK. (Refer to Figure 6-3.)
a. Reach through the forward baggage compartment. position the power pack within its mounting
brackets (6) and install the bolts (7) that attach it to the mounts.
b. Uncover the connect the various hydraulic lines to the power pack.
c. Connect the gear selector control cable (13) to the control arm (11) on the power pack.
d. Connect the electrical connector (8) at the forward side of the power pack.
e. Fill the reservoir with MIL-H-5606 hydraulic fluid by attaching a hose from a pressure tank to
the filler tube (9) of the power pack. (Refer to Filling Hydraulic Reservoir. Section II.)
f.
Bleed the hydraulic system (Refer to Paragraph 6-103) and check for fluid leaks.
g.
After bleeding the hydraulic system, it may be checked as described in Paragraphs 6-9 thru 6-16.
h. Install the access panels.
Revised: 10/5/83 HYDRAULIC SYSTEM
2B17