Piper Navajo PA-31 Service Manual page 670

PIPER NAVAJO SERVICE MANUAL
TABLE X-II. TROUBLESHOOTING CHART (INSTRUMENTS) (cont.)
Trouble Cause
I
Remedy
MANIFOLD PRESSURE INDICATOR
Excessive error at
existing barometric
pressure.
Excessive error when
engine is running.
Sluggish or jerky
pointer movement.
Pointer shifted.
Line leaking.
Improper damping
adjustment.
Restricted filter element
Replace instrument.
Tighten line connections
Adjust damping screw.
Replace filter
Broken or loose cover
glass.
Vibration or excessive
pressure
Replace glass and re-
seat case.
Dull or discolored
luminous markings.
Age. Replace instrument.
Incorrect reading. Moisture or oil in
line.
Restricted filter element
Disconnect lines and
blow out.
Replace filter
ENGINE OIL PRESSURE GAUGE
Excessive error at
zero.
Excessive scale error
Pointer loose on shaft.
Overpressure or
seasoning of bourdon
tube.
Improper calibration
adjustment.
Replace instrument.
Replace instrument.
Reissued: 10/12/79
INSTRUMENTS
3E8