Hydraulic System Service; Propeller Service - Piper SEMINOLE PA-44-180 Information Manual

SECTION 8
HANDLING, SERV & MAINT

8.17 HYDRAULIC SYSTEM SERVICE

The hydraulic landing gear system reservoir is an integral part of the
electric hydraulic pump assembly. The combination pump and reservoir is
accessible through a panel in the baggage compartment. Fill the reservoir with
MIL-H-5606 hydraulic fluid. The fluid level should be checked periodically or
every 50 hour inspection and replenished when necessary.
To check fluid level, remove the filler plug/dipstick and note fluid level on
dipstick. The filler plug also incorporates a vent. When reinstalling filler plug,
tighten to full tight then loosen 1 1/2 turns to allow proper venting. The
instructions are also placarded on the pump reservoir.

8.19 PROPELLER SERVICE

The gas charge in the propeller cylinder should be kept at the pressure
specified on the placard located in the spinner cap. The pressure in the cylinder
will increase about one-third psi for every degree Fahrenheit increase in
temperature. This effect should be considered when checking pressure. The
charge maintained must be accurate and free of excessive moisture since
moisture may freeze the piston during cold weather. Dry nitrogen gas is
recommended.
CHAMBER PRESSURE REQUIREMENTS WITH
TEMPERATURE FOR COUNTERWEIGHT TYPE PROPELLERS
Temp. °F
70 to 100
40 to 70
0 to 40
-30 to 0
NOTE: Do not check pressure or charge with propeller in feather position.
The gas charge in the unfeathering accumulators should be maintained at
90 - 100 PSI. It is important to use nitrogen only for this purpose since any
moisture in the system may freeze and render it inoperative. Do not check this
charge pressure while engine is running.
REPORT: VB-1616
8-10
Pressure (PSI)
FOR PROPELLER HUBS:
HC-C2Y(K,R)-2CEUF
AND HC-C2Y(K,R)-2CLEUF
41 +/- 1
38 +/- 1
36 +/- 1
33 +/- 1
PA-44-180, SEMINOLE
ISSUED: JULY 12, 1995