(d)
Use parts catalog to obtain proper replacement parts for power pack.
19. Assemblyof Reservoir. (Figure403)
(a)
LubricateO-ring (MS28775-009). Install onto top center stud.
(b)
Install center stud into body (PPN 762-589).
(c)
Lubricate two reservoir O-rings and install.
(d)
Push reservoir into body.
(e)
Drop baffle plate into reservoir. Secure by placing snap ring into center stud.
20. TestingReservoirfor Leakage. (Figure 403)
(a)
Remove drain fitting. Attach test hand pump with 200 psi gauge to drain port.
(b)
Remove cap from reservoir vent fitting at top of reservoir. Operate hand pump until reservoir is completelyfull. (Indicated by fluid coming out of vent fitting.)
(c)
Capreservoir vent fitting.
(d)
Operatetest hand pump to raise pressure in reservoir until pressure gauge indicates maximum 50 psi.
(e)
Check for leaks and ensure no external leakage is found.
(f)
Crack vent fitting to release pressure, remove test equipment, drain reservoir and cap fittings.
(g)
Install hydraulic power pack in airplane.
21. Disassembly of Manifold. (Figure 404)
(a)
Unscrew door solenoid from manifold. Remove plunger return spring.
(b)
Remove pin; remove plunger from spool by carefully pulling it from manifold.
(c)
With hook made from a brass welding rod, withdraw transfer sleeve from manifold by inserting hook into oil hole in transfer sleeve.
NOTE: Ensureend of hook is not over 0.06 inches long. Use hook carefully to prevent scratching bore in manifold. The sleeve is difficult to withdraw due to O-ring friction.
(d)
Remove screw, spring, and time delay plunger by inserting small wooden dowel in center of plunger.
(e)
Remove landing gear selector spool by grasping rack (teeth) end of spool and pulling it from manifold.
NOTE: Do not bend but pull selector spool straight out. The landing gear selector spool, time delay plunger and manifold are matched, lapped parts and must be replaced as an assembly only.
EFFECTIVITY:
040-999
PAGE190 29-10-00
Jan 10/90
PIPER AIRCRAFT
PA42-720 (Advanced Trainer)
MAINTENANCE MANUAL
