Table 4-1. Troubleshooting - continued

TM 5-4120-339-14

Table 4-1. Troubleshooting (continued)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

Step 3.

Inspect and test pressure equalizer solenoid valve (paragraph 3-13c).

Repair or replace damaged or defective pressure equalizer solenoid valve

INSUFFICIENT COOLING

Step 1.

Check for insufficient refrigerant in system (bubbles in sight glass).

Step 2.

If adding refrigerant to the system does not clear up bubbles in sight glass, there may be air

in the system.

Open system and remove refrigerant (figure 4-2), purge system (paragraph 4-8),

evacuate system (figure 4-4), and recharge the system with refrigerant

Step 3.

Check for inoperative fans.

Perform corrective actions listed for malfunction 10 of this troubleshooting table.

Step 4.

Check air conditioner operating pressures for excessive refrigerant in system (table 4-3).

Release excess refrigerant from system until the proper charge is attained

Step 5.

Inspect expansion valve and check superheat (paragraph 4-15).

Repair or replace damaged or defective expansion valve. Adjust expansion valve if

superheat is not correct (paragraph 4-15).

Step 6.

Inspect quench valve and check superheat (paragraph 4-16).

Repair or replace damaged or defective quench valve.

Adjust quench valve if

superheat is not correct (paragraph 4-16).

Step 7.

Inspect and test liquid line solenoid valve (paragraph 3-13d).

Repair or replace damaged or defective liquid line solenoid valve (paragraph 4-17).

4-3