Evaporator Removal; Evaporator Installation - Piper Navajo Chieftain PA-31-350 Service Manual

NAVAJO CHIEFTAIN SERVICE MANUAL
c. Evacuate and charge the system. (Refer to paragraph 14-101 or 14-102.) Check system for leaks.
(Refer to paragraph 14-95.)
d. Install floorboards. carpet, seat tracks, cabin divider panels and seats previously removed and
secure.
14-122. EVAPORATOR.
14-123. EVAPORATOR REMOVAL. (Refer to Figure 14-38.) The evaporators are located in the lower
sections of the air conditioning modules. To remove the evaporator core. it is necessary to remove the module
as an assembly which is located in the cabin area aft of the divider panel beneath the second and third seats.
a.
Remove the seat(s) from the airplane.
b. Remove the appropriate cabin divider panel.
c. Remove the seat tracks and carpet from the floorboard panel.
d.
Remove the screws securing the floorboard panel over the unit and remove the panel.
e. The air conditioning system must be completely discharged before disassembly. (Refer to
paragraph 14-101.)
f.
Remove the inboard end panels of the modules, (three screws each panel).
g.
Remove divider panels (six screws each panel) on right panel disconnect the related electrical
connections.
h.
Loosen and separate tube fittings (the tube flanges are sealed and may require heat to separate).
NOTE
When Loctite refrigerant sealant has been used on a joint it must
be heated to 400
°
F prior to disassembly.
i.
Remove the (4) AN-3 bolts (2 each end) and 2 sheet metal screws attaching the evaporator
mounting bracket to the spar cover. Lift assembly away. (Cap tubing ends.)
j. Remove expansion valve. (Refer to paragraph 14-120.)
k.
Remove the (8) AN-3 bolts attaching the evaporator core to the mounting flanges. (On the right
evaporator remove the temperature control switch capillary tube, which is attached to the top forward side
of the evaporator core with retainer clips.)
NOTE
Protect the evaporator core fins during assembly and disassembly. (A
piece of cardboard taped to each side.) Insure that the fins are not bent or
crumpled. This would cause a low efficiency in the cooling action. If
fins are bent. comb the fins with an air conditioning comb. These can be
purchased locally at any air conditioning dealer.
14-124. EVAPORATOR INSTALLATION.
a.
With the module shroud removed, place the evaporator core in the respective mounting brackets.
with the tube fittings on the inboard side and the drain tubes aft. Secure with (8) AN3-3A bolts. (In the
right module attach the temperature control switch capillary tube to the second tube from the forward side
of the evaporator core, with the special clips, placed approximately 6 inches apart (P/N 44843).
b.
Install the evaporator assembly on the spar cover and mating air duct and secure to this spar
cover.
c.
Apply Loctite refrigerant sealant to all tube flanges. Couple the fittings and torque in accordance
vith Table XIV-X.
d.
Secure the expansion valve capillary. (Refer to paragraph 14-121.)
Reissued: 9/23/80
ACCESSORIES AND
UTILITIES
4 H15