Cylinder Head Temperature Gauge; Fuel Flow Gauge Installation - Piper Navajo Chieftain PA-31-350 Service Manual

NAVAJO CHEFTAIN SERVICE MANUAL
10-86. CYLINDER HEAD TEMPERATURE GAUGE.
10-87. GENERAL. The cylinder head temperature gauge is in the instrument cluster, located on the
instrument panel. This instrument measures the cylinder head temperature using a sender located in a
cylinder head. The cylinder head used is determined by the engine manufacturer. This gauge is an electrical
instrument and is wired thru the instruments circuit breaker.
10-88. TROUBLESHOOTING.
TABLE X-XVI. CYLINDER HEAD TEMPERATURE GAUGE
Trouble
Cause
Remedy
Instrument shows no
indication.
Engine is cold.
Warm up engine.
Power supply wire
open.
Defective sender.
Defective instrument.
Open circuit breaker.
Repair wire.
Replace sender.
Replace instrument.
Troubleshoot for fault.
Instrument goes all
the way to upper stop.
Wire grounded between
sender and gauge.
Repair wire.
Defective sender.
Replace sender.
10-89. REMOVAL AND REPLACEMENT. (Refer to paragraph 10-94 of this section.)
10-90. FUEL FLOW GAUGE.
10-91. GENERAL. The fuel flow gauge is a non-electric differential pressure gauge mounted in the bottom
of the instrument panel.
This instrument measures flow by reading the pressure drop across a fixed orifice located in the fuel
divider. With a constant fuel pressure being supplied by the engine driven pump, and putting a fixed orifice
in the fuel divider head, and then measuring the pressure drop downstream of the orifice against a constant
static pressure, the resultant pressure can be calibrated in gallons per hour flow. The constant static pressure
is supplied by a vent line running to the engine compartment. The vent line to the engine compartment
automatically compensates the instrument for altitude.
10-92. INSTALLATION OF FUEL FLOW GAUGE.
a.
Thread tru-seal nut onto fittings until about four and one-half threads protrude beyond the
teflon seal.
b.
Thread fittings a minimum of three threads engagement into port of fuel flow gauge.
c.
Using light to medium torque, tighten down tru-seal nut against port to complete leak-proof
assembly.
Reissued: 9/23/80
INSTRUMENTS
3C2