INSUFFICIENT COOLING - TM-5-4120-356-140093

TM 5-4120-356-14

T a b l e 4-1. Troubleshooting (continued)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

INSUFFICIENT COOLING (continued)

I f adding refrigerant to the system does not clear up bubbles in

Step 2.

the sight glass, there may be air in the system.

O p e n system and remove

refrigerant (figure 4-2). Purge the

s y s t e m in accordance with

paragraph 4-8, evacuate the system

the system with refrigerant in

a c c o r d a n c e with paragraph

Step 3.

Check for inoperative fans.

Perform corrective actions listed in section 10 of this

troubleshooting table.

Step 4.

Check air conditioner operating pressures for excessive refriger-

ant in the system in accordance with paragraph 4-12f.

R e l e a s e excess refrigerant from the system until the proper

charge is attained (figure 4-2).

Step 5.

Inspect expansion valve and check superheat (paragraph 4-14j).

R e p a i r or r e p l a c e d a m a g e d o r d e f e c t i v e e x p a n s i o n v a l v e . A d j u s t

expansion v a l v e i f s u p e r h e a t i s n o t c o r r e c t i n a c c o r d a n c e w i t h

I n s p e c t quench v a l v e and check superheat (paragraph 4-14k).

Step 6.

R e p a i r or r e p l a c e d a m a g e d o r d e f e c t i v e q u e n c h v a l v e . A d j u s t

quench valve if superheat is not correct in accordance with

Step 7.

Inspect and test pressure equalizer solenoid valve in accordance

R e p a i r or replace damaged or defective solenoid valve in

a c c o r d a n c e with paragraph 4-14c.

Inspect and test liquid line solenoid valve in accordance with

Step 8.

R e p a i r or replace damaged or defective solenoid valve in

a c c o r d a n c e with paragraph 4-14b.

4-3