Operation CHARM: Car repair manuals for everyone.

High Pressure Side Restriction


COMPLAINT--Cooling is not adequate.





Condition
- The low side gauge reading is low.
- The high side gauge reading will build up to an excessively high reading.
- The discharge air only slightly cool.
- The high pressure liquid hose from the dryer bottle to the evaporator is cool to the touch or shows signs of heavy sweating or frost.

Diagnosis--A restriction in the receiver/dryer or the high pressure liquid hose from the dryer bottle results in the compressor removing refrigerant from the evaporator faster than it can enter. This results in a starved evaporator.

Correction
- Depressurize the system.
- Renew the dryer bottle and/or the high pressure liquid hoses or other defective parts.
- Evacuate the system using a vacuum pump.
- Recharge the system with new refrigerant.
- Operate the system and check the performance.