Oil Cooler Installation; Oil Pressure Senders Removal; Oil Pressure Sender Test - Piper PA-44-180 SEMINOLE Maintenance Manual

GENERAL.
OIL COOLER.
INSTALLATION OF OIL COOLER.
1. When installing fittings in the oil coolers, care should be used to prevent excessive torque being applied to
the cooler. When a rectangular fitting boss is provided, a backup wrench should be used, employing a
scissor motion, so that no load is transmitted to the cooler. When the oil cooler has a round fitting boss, care
should be taken not to permit excessive torque on the fittings.
2. If a pipe thread fitting is used, it should be installed only far enough to seal with sealing compound.
3. Apply Lubon No. 404 to all male pipe thread fittings, do not allow sealant to enter the system.
4. When installing hoses and fittings make sure a minimum of .5 inch clearance is maintained between hose
and engine mount, and .12 inch between hose and oil filter case.
5. If fitting cannot be positioned correctly using a torque of 10 to 15 foot-pounds, another fitting should be
used.
6. When attaching lines to the cooler, a backup wrench should be used.
7. After installation, inspect the cooler for distorted end cups.
8. Run-up engine, after run-up check for oil leaks.
Winterization plates should be installed between oil cooler seal and engine baff l e
when ambient temperature is below 50° F.
INDICATING.
OIL PRESSURE.
REMOVAL OF OIL PRESSURE SENDERS.
There are two sending units for each engine. One for oil pressure and the other for a warning light. Both units
are mounted on a common manifold located behind each engine firewall. The upper unit is for the pressure
gauge and the lower unit is for the warning light. Access to the units is through access panels on each side of the
forward nacelle. Removal is accomplished by the following:
1. Disconnect the electrical leads from the particular unit. It is suggested that the leads be marked for easy
connection upon reinstallation of the sensor.
2. Unscrew the unit from the manifold.
3. catch spillage and cover the fitting on the manifold to prevent foreign matter from entering the system.
OIL PRESSURE SENDER TEST. (Refer to Chart 7901)
The oil pressure sender works on the relationship of pressure to resistance. As the pressure increases so does
the resistance and inturn alters the position of the needle of the instrument.
To test the sender the following procedure should be followed:
1. Connect a calibrated pressure source to the pressure port.
2. Attach ohmmeter leads to the one pole extending from the sender and one to the sender itself.
3. Raise and lower the pressure to the sender and crosscheck with the required tolerances in Chart 7901.
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
— Note —
3I3
7 9 - 3 1 - 0 2
Page 79-01
Revised: May 15, 1989