TM 9-4120-398-14
TABLE 5-1. DIRECT SUPPORT TROUBLESHOOTING (cont)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
5.
SIGHT GLASS APPEARS YELLOW INSTEAD OF GREEN.
Death or serious injury may result if personnel fail to observe safety precautions. Use great care to
avoid contact with liquid refrigerant or refrigerant gas being discharged under pressure. Sudden and
irreversible tissue damage can result from freezing. Wear thermal protective gloves and a face protector
or goggles in any situation where skin-eye contact is possible.
Prevent contact of refrigerant gas with flame or hot surfaces. Heat causes refrigerant to break down
and form carbonyl chloride (phosgene), a highly poisonous and corrosive gas.
Step 1.
Yellow appearance of sight glass is caused by contamination in the refrigerant.
a. Release refrigerant. (See paragraph 5-5.)
b. Remove filter-drier. (See paragraph 5-21.)
c. Purge and dry system. (See paragraph 5-6.)
d. Install new filter-drier. (See paragraph 5-21.)
e. Leak test system. (See paragraph 5-8.)
f. Evacuate system. (See paragraph 5-9.)
g. Recharge with refrigerant. (See paragraph 5-10.)
Step 2.
Check for yellow in sight glass after allowing compressor to run for at least 1 hour.
Repeat corrective action in step 1.
AIR CONDITIONER NOISY DURING OPERATION.
6.
Step 1.
Check expansion valve. (See paragraph 5-13.)
Replace if defective.
5-5
