If the extension solenoid of the pump can be heard to actuate when operating the gear selector switch, it may be assumed that the gear control circuit is operating properly and the actuator circuit should be further checked.
Gear selector switch ground Check ground. incomplete.
Gear selector switch inoperative. Replace switch. Hydraulic pump ground Check ground. incomplete.
Hydraulic pump inoperative. Replace or overhaul pump.
Hydraulic fluid in reservoir below Fill reservoir with operating level. hydraulic fluid. Low or dead battery. Check condition of battery.
Landing gear retraction Hydraulic fluid in reservoir Fill reservoir with
extremely slow. below operating level. hydraulic fluid.
Restriction in hydraulic lines. Isolate and check hydraulic
lines.
Shuttle valve sticking in pump Check cause.
base.
32-30-00 Page 32-56 Revised: December 6, 2002
2I8
THE NEW PIPER AIRCRAFT, INC.
PA-44-180
AIRPLANE MAINTENANCE MANUAL
CHART 3203. TROUBLESHOOTING (EXTENSION & RETRACTION) (Sheet 3 of 5)
Trouble Cause Remedy
Pump stops during gear Landing gear actuator circuit Reset circuit breaker and
retraction. breaker opens. determine cause for overload.
Landing gear selector circuit Reset circuit breaker and
breaker opens. determine cause for overload.
Pressure switch out of Remove, readjust or replace
adjustment. (1) switch.
Mechanical restriction or Place airplane on jacks and
obstruction in hydraulic system run retraction check.
to allow pressure to up and shut Isolate and determine
off pump before gear has retracted. cause.
Shuttle valve sticking in pump Check cause.
base.
(1) When seen in Oildyne pump, pump may require overhaul.
Pump stops during gear extension. Landing gear actuator circuit breaker opens. Reset circuit breaker and determine cause for overload.
Landing gear selector circuit breaker opens. Reset circuit breaker and determine cause for overload.
Pump fails to shut off though gear has fully retracted. Pressure switch inoperative. Replace switch.
Pressure switch out of adjustment. Replace switch.
Pump retraction inboard solenoid sticking. Replace solenoid.
Internal leakage of system. Check free fall valve for internal leakage.
Check gear actuating cylinders for internal leakage.
Replace pump or return pump to Piper via local Piper distributor for overhaul.
32-30-00 Page 32-57 Revised: December 6, 2002
THE NEW PIPER AIRCRAFT, INC.
PA-44-180
AIRPLANE MAINTENANCE MANUAL
CHART 3203. TROUBLESHOOTING (EXTENSION & RETRACTION) (Sheet 4 of 5)
Trouble Cause Remedy
Pump fails to shut off though External leakage of system. Check free fall valve for
gear has fully retracted. (cont.) external leakage. Check gear actuating cylinders for external leakage.
Check for broken or damaged hydraulic lines or hoses.
Pump relief valve out of Replace pump. adjustment.
Pump fails to shut off though Pump extension lower solenoid Replace solenoid. the gear has fully extended. sticking.
Nose gear down limit switch Adjust switch actuator.
actuator out of adjustment. (Refer to Adjustment of Nose Gear Down Limit Switch.)
Nose gear down limit switch Replace switch. failed.
Main gear down limit switch out Adjust switch. (Refer to of adjustment. Adjustment of Main Gear Down Limit Switch.)
Main gear down limit switch Replace switch. failed.
Pump running intermittently Leakage of high pressure Replace pump or return
after gear has retracted. check valve. pump to Piper via local Piper distributor for overhaul.
Internal leakage of system. Check free fall valve for internal leakage.
Check gear actuating cylinders for internal leakage.
External leakage of system. Check free fall valve for external leakage.
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