Power Pack Bench Test Adjustment; Adjustment Of Handle-Release Mechanism - Piper Navajo Chieftain PA-31-350 Service Manual

NAVAJO CHIEFTAIN SERVICE MANUAL
6-45. POWER PACK BENCH TEST ADJUSTMENT. After completion of the overhaul, the power pack
may be bench tested prior to installation in the airplane by using a hydraulic test unit or similar test
equipment. This procedure requires a minimum of test equipment for testing the power pack.
a. Use only clean hydraulic fluid (MIL-H-5606).
b. Minimum equipment needed is as follows:
1. Test unit pump or hand pump with a 3000 psi capacity.
2.
One hydraulic pressure gauge of 3000 psi capacity.
3. One hydraulic pressure gauge of 150 psi capacity.
c. Connect the test pressure hose to the pressure inlet port of the power pack. The 3000 psi gauge is
to operate off of the pressure line.
d. Connect the suction hose to the suction port of the power pack.
e.
If a vent hose is part of the test unit, connect it to the vent port at the top of the power pack.
f. Cap all other fittings with high pressure caps.
NOTE
For control of the door valve solenoid it will be necessary to
fabricate an electric harness as shown in Figure 6-29. This harness,
when connected to a 24-volt battery, will allow control of the
electrical current to the door valve solenoid, permitting operation
of the door hydraulic circuits.
6-46. ADJUSTMENT OF HANDLE-RELEASE MECHANISM. (Refer to Figure 6-1 1.)
The following procedure outlines preliminary adjustments to set the handle-release detent spring load
and the handle-return spring load adjusting plugs in approximately their correct positions before installing
the power pack in the airplane. After it has been installed, the system must be checked and final
adjustments, if needed, made at that time. Use a .078 inch punch to rotate the gear handle shaft.
a. Ascertain that the handle-return spring adjusting plugs (1 and 2) are not tightened, and the detent
spring adjusting plug (3) has been screwed in until approximately .312 inch of thread is engaged. The
spring, however. must not bottom out.
b. Place the handle in the up-detent position, then hold it beyond this position (in overtravel).
c. Tighten the forward handle-return spring adjusting plug (2) until the handle just starts to move
out of overtravel, then loosen the adjusting plug one turn.
d. Place the handle in the down-detent position, then hold it beyond this position (in overtravel).
e. Tighten the aft handle-return spring adjusting plug (1) until the handle just starts to move out of
overtravel, then loosen the adjusting plug one turn.
f.
Place the handle in the up-detent position and tighten the handle-release detent spring adjusting
plug (3) until the spring bottoms out, then back the adjusting plug out two turns.
g. The handle must hold in both detent positions, but must return with a positive snap when
manually released from either detent position. Connect a spring scale to the arm and pull both fore and aft,
perpendicular to the centerline of the arm, to determine that it will leave the detent at a force of 9 + 1-2
pounds. The handle-release detent spring adjusting plug (3) may be readjusted slightly more or less than the
two turns specified in the preceding steps, if necessary. When proper detent adjustment has been obtained,
tighten the nuts and safety.
Reissued: 9/23/80
HYDRAULIC SYSTEM
2B 15