TM 9-4120-404-14
Table 4-1. Direct Support Troubleshooting.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 3. Test for defective expansion valve.
Test for properly functioning expansion valve per para. 4-26.
Replace defective expansion valve.
If expansion val ve is not defective, replace compressor (see para. 4-28).
4. SUCTION PRESSURE TOO LOW.
Step 1. Airflow across evaporator coil is restricted.
Check for clogged evaporator coil. Clean as required.
Check for defective evaporator fan motor. Replac e if defective (see para. 4-12).
Check for clogged mist eliminator. Clean as required.
Check for clogged return air filter. Clean as required.
Step 2. Check for restricted dryer.
Replace dryer if clogged (see para. 4-18).
Step 3. Check for defective expansion valve.
Test for defective expansion valve. Replace if defective (see para. 4-26).
Step 4. Check for mashed or crimped refrigerant tubing.
Repair or replace any damaged tubing (see para. 4-31).
Step 5. Check for low refrigerant charge.
Refer to servicing refrigerant system para. 4-6 and recharge system as
required.
4-3
