Fuel Flow Gauge Troubleshooting; Removal And Replacement Of Face Mounted Instruments - Piper Navajo Chieftain PA-31-350 Service Manual

NAVAJO CHIEFTAIN SERVICE MANUAL
10-93.. TROUBLESHOOTING.
TABLE X-XVII. FUEL FLOW GAUGE
Trouble
Cause
Remedy
Pointer oscillates.
Air in fuel line.
Purge line.
Gauge reads low at
Vent line restricted.
Check line and fittings.
altitude.
Pointer does not
Fuel in diaphragm of
Replace gauge.
return to zero.
gauge.
10-94. REMOVAL AND REPLACEMENT OF FACE MOUNTED INSTRUMENTS.
10-95. GENERAL. Since all instruments are mounted in a similar manner, a description of a typical
removal and installation is provided as a guide for the removal and installation of the instruments. Special
care should be taken when any operation pertaining to the instruments is performed.
a.
Remove the face panel.
b.
With the face panel removed. the mounting screws for the individual instruments will be exposed.
Remove the connections to the instrument prior to removing the mounting screws of the instrument to be
removed. It is required to immediately plug all exposed gyro ports with plastic or metal plugs to prevent
contamination. Failure to do so will void warranty! (Refer to 10-99.)
NOTE
Tag instrument connections for ease of installation.
CAUTION
DO NOT use thread lube on fittings or in ports of gyros. The use of thread lube
can cause contamination which shortens the life expectancy of the gyro and
cause premature failure. Any evidence of thread lube will create a
WARRANTY VOID CONDITION. Make sure that all air lines are clean and
free of oil, grease, pipe compound, or any foreign particles/or residue before
connecting lines to gyro.
c.
The use of teflon tape on gyro fitting threads is recommended and should be installed in the
following manner:
1.
Carefully lay teflon tape on the threads, allowing one thread to be visible from the end of the
fitting. Hold in place and wrap in the direction of the threads, so tape will remain tight when fitting is installed.
2.
Apply sufficient tension while winding, to assure that the tape forms into thread's grooves. One
full wrap plus I /2" overlap is sufficient.
3.
After wrap is complete, maintain tension and tear tape by pulling in direction of wrap. The
ragged end is the key to the tape staying in place. (If sheared or cut, tape may loosen.)
4.
Press tape well into threads.
5.
Screw fitting into port being careful not to exceed torque requirements as noted on decal
located on cover of gyro.
Revised: 10/15/82
INSTRUMENTS
3C3