TM 9-4120-357-14
(8) Connect power input plug to air conditioner.
WARNING
Hearing protection must be worn when maintenance is performed while air conditioner is
in operation. Failure to heed this warning can result in hearing loss or injury.
CAUTION
Connect power to unit as soon as possible after charging or any period when power has
been disconnected. Allow heater time to vaporize refrigerant in compressor before opera-
tion in COOL mode. If knocking or pounding is heard at start of COOL mode, turn selec-
tor switch to OFF or VENTILATE at once and allow additional warm up time.
(9) With power connected to the air conditioner, turn mode selector switch to cool. Turn temperature control
thermostat to maximum decrease position. Temporarily prop the front access panel across the opening. With compres-
sor operating, observe-the sight-glass liquid indicator. If bubbles or milkiness appear, top off the refrigerant charge as
follows:
(a) Connect a cylinder of refrigerant, R22, loosely to the gage port of the suction line service valve. Open
the cylinder shutoff valve for a few seconds to purge air from the line. Tighten the connection. Leave the cylinder up-
right, or connect line to the vapor valve.
(b) With the air conditioner compressor operating, open the suction line service valve and the cylinder shut-
off valve to charge refrigerant gas into the system, while observing the sight-glass liquid indicator.
(c) When liquid in sight-glass indicator runs clear and free of bubbles, close the suction line service valve
and the cylinder shutoff valve
(d) Disconnect the refrigerant cylinder. Replace caps on both service valves.
h. Final Assembly. Position the front access panel on the air conditioner. Secure with four panel fastener screws.
5-28. Evaporator Coil.
a. Access. Obtain access to the evaporator coil as indicated in the following instructions:
(1) Remove 31 screws and washers from the top panel, and remove top panel.
(4) Unscrew four panel fastener screws from the front access panel, and remove panel.
(5) Remove 12 screws and washers from the right-hand evaporator intake grille, and remove the grille.
b. Discharging the System. Whenever a leak is detected or a refrigeration component must be replaced, discharge
all gas from the refrigeration system in accordance with paragraph 5-6.
(1) Disconnect heater assembly wiring harness plug, P7, from its receptacle in the wall of the right-hand return air
plenum.
(2) Remove two screws which secure the heater support bracket, (8, Figure 4-14) . Pull the entire heating as-
sembly up, and remove it from the air conditioner.
(3) Remove six screws from the mounting brackets on each side of the evaporator coil.
(4) Remove the two capscrews holding the power assembly of expansion valve, V5 (14, Figure 4-7) to the valve
body.
(5) Remove the two capscrews that secure the expansion valve body to the support bracket.
(6) Remove insulation from the suction line.
5-60
