Piper Navajo PA-31 Service Manual page 659

PIPER NAVAJO SERVICE MANUAL
CAUTION
When replacing leads, it is very important to use the same type and
length of thermocouple wire, as the resistance of the leads is critical
for the proper operation of this gauge.
10-28. REMOVAL OF EGT PROBE AND GAUGE.
a.
Disconnect wires from the EGT gauge at the instrument panel.
b. Remove four bolts which secure the gauge to the instrument panel and remove the gauge.
c. Remove wires from the wire harness going to the engine.
d.
Loosen the nut which secures the EGT probe to the exhaust transition area of the exhaust system
and remove the probe. (Note depth of probe in gland nut.)
10-29. CLEANING AND INSPECTION. Unless mechanical damage is evident, broken glass, bent or broken
pointers, or broken case, the following checks should be performed before removing the instrument.
a. Remove the probe from the exhaust transition area and check for broken weld (at tip end) or burnt
off end.
b. Disconnect the lead wires at the instrument and check for poor electrical connections.
c. With leads connected to the instrument, heat the probe with a propane torch to a dull red. The meter
should show a reading. If the point does not move, replace the meter.
CAUTION
Do not connect an ohmmeter across the meter. It will burn out the
movement of the meter.
10-30. INSTALLATION OF EGT PROBE AND GAUGE.
a. Install the probe into the hole in the transition area of the exhaust system and secure with locknut.
The probe is located between the turbocharger and wastegate.
b. Route the thermocouple wires along with the existing wire harness to the instrument panel.
c. Install the EGT gauge into the instrument panel and secure with four bolts.
d. Connect the thermocouple wires to the rear of the EGT gauge.
10-31. REMOVAL OF MANIFOLD AND CHECK VALVE ASSEMBLY.
a. Insure that master switch is turned off.
b. Remove upper foremost access panel on each side of pedestal housing.
c.
Slide spring clamps off of hoses and remove hoses from manifold and check valve assembly.
d. Remove two bolts which secure manifold and check valve assembly to mounting bracket.
e. Note position of wires on pressure switches. Remove attachment screws and remove wires from
switch terminals.
f. Remove manifold assembly from pedestal housing.
10-32. INSTALLATION OF MANIFOLD AND CHECK VALVE ASSEMBLY.
a.
Insert manifold assembly through pedestal housing access hole and secure electrical wiring to
pressure switch terminals with screws and washers.
b.
Place manifold assembly into position on mounting bracket and secure with two bolts.
c. Install five connecting hose sections on manifold tubing and secure with spring clamps.
Revised: 10/12/83
3D21
INSTRUMENTS
3D21