Piper SEMINOLE PA-44-180, Maintenance Manual

Page: 151 / 881

REPAIR OF COMBUSTION TUBE ASSEMBLY.
— Note —
No weld or braze repairs are authorized.
REASSEMBLY OF HEATER. (Refer to Figure 21-18)
1. If removed during disassembly, secure the nipple and elbow to the fuel solenoid.
2. Insert the ventilating air motor into the motor bracket assembly; slide the blower wheel on the end of the
motor shaft and rotate it until the set screw is aligned with the flat side of the motor shaft. Tighten the set
screw just tight enough to hold it at this time.
3. Attach the capacitor and leads assembly to the motor bracket with screw and lock washer. Make sure a
good electrical ground connection is made at this point. Install ground bracket and three new fasteners.
4. Insert this assembly into the blower housing.
5. Make sure all wires are routed and grommeted as they were prior to disassembly and then secure the
assembly in the housing with three screws.
6. The motor should be positioned in the bracket to locate the blower wheel properly in the blower housing.
The blower wheel should be positioned so it will rotate freely and just clear the contoured spill plate in
the blower housing. Tighten the Allen-head set screw and spin the blower wheel by hand for a clearance
check. Then apply the appropriate voltage to run the motor as a final clearance check.
7. Attach the inlet adapter to the end of the blower housing with three screws and lock washers.
8. Place a new asbestos gasket in position on the exhaust outlet; spring the jacket assembly open at the seam
and insert the combustion tube assembly carefully into the jacket. Exercise care to clear the pressure
switch tube in the exhaust outlet and see that the asbestos gasket is properly located. Close the gap on the
jacket assembly and install screws to secure it at the seam. (Solenoid lead wire is grounded under one of
these screws. See notations made during disassembly.) Make sure the seam is in good condition and a
tight fit is effected.
9. Install cable straps at locations noted during disassembly.
— CAUTION —
THE SPRAY NOZZLE HAS A SLIGHT PROTRUSION ON THE NOZZLE
FACE. IF THIS AREA HAS BEEN STRUCK BY ANY OBJECT WHICH
WOULD MAKE A DENT OR DESTROY THE ORIGINAL CONTOUR, THE
NOZZLE MUST BE REPLACED.
10. Remove the spray nozzle from the polyethylene bag. Screw the nozzle into the nozzle holder and tighten
to 75-100 inch-pounds. It is very important to torque the nozzle to this value as incorrect tightening
could cause improper heater operation and nozzle “drool.”
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
2 1 - 4 4 - 0 8
Page 21-40
Revised: May 15, 1989
1G7
PIPER AIRCRAFT