Landing Gear Retraction Extremely Slow; Pump Stops During Gear Retraction; Pump Stops During Gear Extension; Pump Fails To Shut Off Though Gear Has Fully Retracted - Piper PA-44-180 SEMINOLE Maintenance Manual

CHART 2902. TROUBLESHOOTING HYDRAULIC SYSTEM (cont.)
Trouble
Landing gear retraction extremely
slow.
Pump s t o p s d u r i n g
r e t r a ction.
P ump s t o p s d u r i n g
e x t e nsion.
Pump fails to shut off though
gear has fully retracted.
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
Cause
Hydraulic fluid in reservoir
below operating level.
Restriction in hydraulic lines.
Shuttle valve sticking in pump
base.
gear Landing gear actuator circuit
breaker opens.
Landing gear selector circuit
breaker opens.
(1) P r e s s u r e s w i t c h out of
a d j u s tment.
Mechanical
obstruction in hydraulic system
to allow pressure to up and shut
o ff pump before gear has retracted.
Shuttle valve sticking in pump
base.
( 1 ) Oildyne pumps may re q u i re
overhaul.
gear Landing gear actuator circuit
breaker opens.
Landing gear selector circuit
breaker opens.
Pressure switch inoperative.
P r e s s u r e s w i t c h
a d j u s tment.
Pump retraction inboard solenoid
sticking.
2C3
Fill reservoir with hydraulic
fluid.
Isolate and check hydraulic lines.
Check cause.
Reset circuit breaker and deter-
mine cause for overload.
Reset circuit breaker and deter-
mine cause for overload.
Remove and readjust or replace
switch.
restriction or Place airplane on jacks and run
retraction check. Isolate and
determine cause.
Check cause.
Reset circuit breaker and deter-
mine cause for overload.
Reset circuit breaker and deter-
mine cause for overload.
Replace switch.
out of Replace switch.
Replace solenoid.
Remedy
29-02-00
Page 29-08
Revised: June 20, 1995