Condenser Malfunction or System Overcharge

COMPLAINT--Little or no cooling. Overheating of the engine may also be noted.




Condition
- The low side gauge reading excessively high.
- The high side gauge reading is also excessively high.
- Bubbles may appear occasionally in the sight glass and the liquid line to the evaporator is very hot.
- The discharge air from the evaporator is warm.

Diagnosis--The condenser is not operating correctly through lack of cooling caused by too high of a high side pressure. The system may have either a normal or overcharge of refrigerant.

Correction
- Check the compressor drive belt for correct tension.
- Check the condenser for clogged air passages preventing air flow through the condenser.
- Inspect the condenser mounting for correct radiator clearance.
- Check the fan for correct operation.
- Check the coolant pressure cap for correct type and operation.
- Operate the system and check the performance.

If the Condition is not Rectified:
- Inspect the system for overcharge of refrigerant and rectify as follows:
1. Discharge the system, until a stream of bubbles appear in the sight glass and both gauge readings drop to below normal.
2. Add new refrigerant until the bubbles disappear and the pressures are normal.
3. Add 0.25 to 0.5 lb of additional refrigerant.
4. Operate the system and check the performance.

If the Gauge Readings are Still to High:
- Depressurize the system.
- Remove and inspect the condenser for oil clogging.
- Clean and flush the condenser to ensure the free passage of refrigerant or renew the condenser.
- Renew the receiver/dryer.
- Evacuate the system using a vacuum pump.
- Recharge the system with new refrigerant.
- Operate the system and check the performance.