Piper Navajo Chieftain PA-31-350 Service Manual page 800

NAVAJO CHIEFTAIN SERVICE MANUAL
c. Carefully disconnect the high voltage ignition lead at the spark plug. Handle the spring connector
on the end of this lead with care to prevent fouling or damage.
d. Remove the four screws and cable straps to free the ignition assembly (4) from the heater jacket
and remove the ignition assembly. The vibrator may be removed by exerting a firm pull straightaway from
the ignition assembly case.
e. Remove the grommet (12) from the jacket (1) and remove the spark plug (6) with a 7/8 inch
deep socket. Make sure the spark plug gasket is removed.
f. Remove the two screws and lift out the overheat (limit) switch (8) and spacer gaskets.
g. Remove the two screws and lift out the cycling switch ( 1).
h. Remove the four screws to release the terminal strip (10) and insulator (9) from the jacket ( 1).
i. Disconnect the fitting at the combustion air pressure switch (17). (Refer to Paragraph 13-34, for
caution on the combustion air tube bending.) Unscrew and remove the combustion air pressure switch (17)
from the combustion air inlet tube.
j. Loosen the four fasteners and rotate the blower and motor housing (41) to disengage the notched
end from the four screws in the end of the heater jacket. Separate the electrical quick-disconnect on motor
lead wires. Remove blower assembly. Remove grommet from fuel shroud (45) and carefully pull fuel
solenoid wires through hole in shroud. With open wrench, remove fuel solenoid (47).
k. Reach inside the inlet end of the jacket assembly (1) with a 3/4 inch open wrench to hold the
fuel tube fitting at the jacket: then remove the elbow fitting (44), nut (48), washer (50), gasket (42) and
fuel shroud.
1. Remove the two screws and carefully withdraw the nozzle holder assembly (18) from the
combustion tube assembly (20). Remove the gasket (49).
m. Remove the screws and remaining cable straps (5) if not previously removed from the seam of the
jacket assembly (1). Note positions of cable straps as they are removed. Spread the jacket (1) at the seam
and remove it from the combustion tube assembly (20); this will free the rope gasket (21), which can be
removed from the particular port on which it remains attached.
n. Carefully unscrew and remove the spray nozzle (23) from the nozzle holder and solenoid valve
assembly.
CAUTION
Handle the nozzle with care to avoid damage to the tip. The
material around the orifice is very thin and any sharp blow on the
face of the nozzle can distort the spray pattern and cause
malignition or improper combustion.
o. Loosen and remove the three screws (39) and rubber grommet (38) from the blower housing
(41).
p. Slide the ventilating air blower motor out of the blower housing (41) with the motor bracket
assembly (33) and blower fan (34) attached. Loosen the set screw on the blower fan (34) and slide it off
the end of the motor shaft; then remove the motor bracket assembly (33). If these parts are in good
condition, they need not be disassembled further.
Reissued: 9/23/80 HEATING AND VENTILATING SYSTEM
4C8