Piper SEMINOLE PA-44-180, Maintenance Manual

Page: 335 / 881

CHART 2902. TROUBLESHOOTING HYDRAULIC SYSTEM (cont.)
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
29-02-00
Page 29-08
Revised: June 20, 1995
2C3
Trouble
Landing gear retraction extremely
slow.
P u m p s t o p s d u r i n g g e a r
r e t r a ction.
P u m p s t o p s d u r i n g g e a r
e x t e nsion.
Pump fails to shut off though
gear has fully retracted.
Cause
Hydraulic fluid in reservoir
below operating level.
Restriction in hydraulic lines.
Shuttle valve sticking in pump
base.
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 o u t of
a d j u s tment.
Mechanical restriction or
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.
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 o u t of
a d j u s tment.
Pump retraction inboard solenoid
sticking.
Remedy
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.
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.
Replace switch.
Replace solenoid.