Manifold Pressure Gauge - Piper Comanche PA-24 Service Manual

11-45. Manifold Pressure Gauge.

11-46. General.
The manifold pressure gauge is a vapor proof. absolute pressure type instrument Pressure from the
intake manifold of the engine is transmitted to the instrument through a line. A pointer indicates the
manifold pressure available at the engine in inches of mercury.
11-47. Removal And Replacement.
Refer to Paragraph 11-18.
11-48. Troubleshooting.
See Table XI-VIII.
Table XI-VIII. Troubleshooting Manifold Pressure Indicator
Trouble
Excessive error at existing
barometric pressure.
Excessive error when
engine is running.
Sluggish or jerky pointer
movement.
Broken or loose cover
glass.
Dull or discolored
luminous markings.
Incorret reading.
XI - INSTRUMENTS
PIPER COMANCHE SERVICE MANUAL
Cause
Pointer Shifted
Line leaking.
Improper damping adjustment.
Vibration or excessive
pressure.
Age.
Moisture or oil in line.
3G12
Remedy
Replace instrument.
Tighten line connections.
Adjust damping screw.
Replace glass and reseat
case.
Replace instrument.
Disconnect lines and blow
out.
04/01/09