TM 9-4120-360-14
5.90. Servicing
Service the evaporator coil after removal from the air conditioner, as directed below:
a. Cleaning. Cap or plug all openings, and tape caps or plugs to prevent accidental removal. No water must be
permitted to enter the coil. When thoroughly sealed, immerse the coil in warm detergent solution for five minutes to soak
loose caked-on dirt, then agitate the coil vigorously in the solution to remove dirt from between the fins. Rinse
thoroughly in clear water.
b. Fin Aligmnent. If fins are bent or crushed, straighten them with a wood or plasti blades so that they are straight
and parallel. Badly bent or crushed fins can cause serious distortion of airflow, resulting in inefficient operation of the air
conditioner.
5.91. Disassembly
If a new coil is to be installed, debraze the distributor assembly front the old coil at three places. Remove miste eliminator
retaining channels from the coil by removing four screws from each channel.
5.92. Assembly
Assemble the evaporator coil in the following manner.
a. Position the mist eliminator channels on the front of the evaporator coil, at each end, and secure with four
screws through each channel.
b. Install a new O-ring in th egroov eof the suction line connecting flange, and assemble the halves of the flange.
Secure with three capscrews from the back of the partition.
NOTE
If a new liquid line expansion valve body is to be installed, braze the distributor body into the discharg port
of the expansion valve before assembling the valve.
c. Position the liquid line expansion valve body (9, figure 5-9)on its support bracket, and align by securing with
two screws (10) and slave nuts. Do not install power assembly at this time. Braze liquid line to valve body.
d. Install new gaskets (6) and seat (8) in valve body.
Place cage assembly (7) in power assembly (1), remove screws (10) and fit bosses of cage assembly into
recesses in valve body. Secure power assembly (1) to valve body (9) with screws (10). Connect the equalizer line flare
nut.
f. Install the evaporator/condenser fans and motor. (Refer to
Chapter 5, Sections XX
through XXII.)
g. Purge the refrigeration system with dry nitrogen at
1-2 cfm (0.1 -0.2 M
3/min) for 15 minutes.
i. Install the mist eliminator by sliding it straight down in the channels in front of the evaporator coil. Make sure
that TOP mark is up. and that airflow arrows point outward.
Install a new filter-drier, leak-test, and charge the refrigeration system as instructed in paragraphs 5.53
through 5 .55.
k. Position the top panel on the air conditioner. Secure it with 15 screws and packing washers through the top
surface, and five screws through the rear flange.
l. Place the evaporator air discharge grille in
the opening, and secure it by
turning the six cam-lock studs
clockwise.
5-48