c. Flow-testing. Place a 3/4-inch board under one side of the air conditioner to tilt it slightly, then pour about
one pint (one-half liter) of water into the lower end of the drip pan below the evaporator coil. Verify that the water flows
out of the drip pan through the drain tube. Tilt the air conditioner the opposite direction, and repeat the flow test on the
other side. Water should drain freely through both tubes. If it does not. remove and repair or replace the drain tube.
Disassemble the drain tube assembly
in the following manner. (See figure 4-9).
(1) Loosen the two hose clamps (2) on the side to be disassembled. SIide them downward, off the hose.
(2) Bend the two retaining clips far enough to pull the tube away from the casing.
(3) Twist and pull the tube downward to remove it from the hose. If hose remains attached to the lower tube,
remove from the air conditioner and twist or cut the hose from the tube.
(4) Place a container below the end of the upper drain tube (1) and repeat the water flow-test to make sure
that the obstruction is not in the upper tube. If it is. remove it with a flexible wire with a small hook on the upper end.
(5) If the obstruction is in the lower drain tube, straighten the ends of the cotterpin, hold one hand over the
lower end of the check valve assembly to prevent loss of the spring (7), and withdraw the cotterpin (5). Remove the ball
(6), and push a flexible wire upward through the tube to dislodge the obstruction. Flush the tube thoroughly with hot
e. Assembly. Assemble the drain tube assembly in accordance with the following procedure:
(1) Insert ball and spring into body of check valve.
(2) Compress the spring below the level of the cotterpin, insert the cotterpin through both walls of the check
valve, and spread the ends of the cotterpin.
(3) Slide a length of hose over the upper drain tube, install a hose clamp over the upper part of the hose, and
tighten the hose clamp.
(4) Slide a second hose clamp over the lower part of the hose, and insert the upper end of the lower drain tube
into the hose. Align the lower end of the drain tube along the side of the casing, and press tube into the clips in the front
corner. Bend clips slightly to retain tube in position then tighten the lower hose clamp.
(5) Install mist eliminator by pushing down into channels in front of the evaporator coil. Make sure that
airflow arrows point away from the coil, and that TOP marking is up.
(6) Install air filter in front of evaporator fan intake. Make sure that airflow arrows point inward, and engage
the left side of the filter in the channel beside the fresh air damper. Install the retaining strip on the right-band side, and
secure with two screws.
(7) Install the air intake and discharge louvers, and secure in place with six cam-lock studs each, by turning
(8) Position the top panel on the air conditioner, and secure with 15 screws and packing washers in the top
surface and five screws through the rear flange.
(9) Fit the fabric cover over the rear surface of the air conditioner so that eyelets match the screw holes in the
casing. Secure with 18 screws and washers.
(l0) Install the lower panel on the air conditioner, and secure with two panel fastener screws in the upper