Oil Pressure Gauge Troubleshooting; Oil Pressure Gauge Calibration - Piper PA-44-180 SEMINOLE Maintenance Manual

TROUBLESHOOTING PRESSURE GAUGE.
Trouble
Excessive error at zero.
Excessive scale error.
Excessive pointer
oscillation.
Sluggish operation of
pointer or pressure fails
to build up.
REMOVAL AND REPLACEMENT.
Refer to the General sectrion of Chapter 77 for Removal of Cluster Mounted Instruments.
OIL PRESSURE GAUGE CALIBRATION. (PA-44-180 S/N 44-95001 AND UP)
A calibration chart has been included for use in verifing that the suspected faulty gauge is within tolerance.
Actual recalibration of the gauge must be performed by the manufacturer or an approved instrument repair
facility.
1. With the instrument installed in the aircraft, the aircrafts' power connected (14 VDC) and the ground
connected.
2. Remove the connection to the terminal marked SEND and connect a specified amount of resistance as
indicated on the chart, by use of a fixed resistor or a test unit capable of simulating the resistance indicated
on the chart (Power Resistor Decade Box).
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
CHART 7902. OIL PRESSURE GAUGE
Cause
Pointer loose on shaft.
Overpressure or seasoning
of burdon tube.
Improper calibration
adjustment.
Air in line or rough engine
relief.
Engine relief valve open.
Line restriction to
instrument.
Loss of oil in engine or
other engine failure.
NOTE
Gauge will take longer to indicate in cold weather.
3I5
Remedy
Repalce instrument.
Replace instrument.
Disconnect line and fill
with light oil. Check for
leaks. If trouble persists,
clean and adjust relief valve.
Clean and check.
Clean and check.
Shut down engine.
Page 79-03
Revised: May 15, 1989
7 9 - 3 2 - 0 2