High Pressure Safety Valve HVAC: Description and Operation

Air Conditioning

A/C Compressor Pressure Relief Valve

NOTE: If the A/C compressor is operating within limits and the A/C pressure relief valve is venting, or if the A/C pressure relief valve is leaking around the threads, install a new A/C pressure relief valve and O-ring. If the A/C pressure relief valve still vents after it is replaced, diagnose the refrigerant system for a restriction.

An A/C pressure relief valve is incorporated in the A/C compressor (4.6L or 5.4L) or compressor manifold and tube assembly (4.0L), as a redundant backup to the A/C pressure transducer, to prevent damage to the A/C compressor and other system components by relieving unusually high system discharge pressure buildups. Under normal conditions the A/C pressure relief valve will never vent. Only a failure of the A/C pressure relief valve, A/C pressure transducer or A/C clutch control system, overheating of the refrigerant system, or a restriction in the refrigerant system between the A/C compressor and A/C pressure transducer will cause the A/C pressure relief valve to vent.

The A/C pressure relief valve is a separate component and can be replaced separately from the A/C compressor (4.6L or 5.4L) or compressor manifold and tube assembly (4.0L). It is necessary to recover the refrigerant before removing the A/C pressure relief valve.