The following instructions were provided in an air conditioning compressor replacement.

1) Always wear eye protection. Identify and remove refrigerant in accordance with any state and federal regulations before working on the vehicle.

2) Remove the failed compressor from the vehicle. Transfer any switches, sensors, brackets, or manifolds from the original compressor to the replacement unit.

On many GM models the high pressure cut out switch (red) is located on the back of the compressor. It must be transferred over to the replacement part.

 3) Thoroughly flush each component not being replaced with an approved AC flush solvent. Once each component has been flushed of all contamination it is necessary to air dry these components using compressed and/or filtered shop air to insure no flushing solvent remains.

4) Replace the accumulator or dryer and all expansion devices. This would include the orifice tube and screen that most vehicles use today. Refer to your car repair manuals for vehicle specific instructions.

5) After installing the replacement compressor on the vehicle ensure proper mounting and belt alignment.

6) It is recommended to install an in-line filter in the suction line near the compressor inlet. This will prevent possible debris from entering and destroying the replacement unit.

7) Add the proper type and amount of ac oil as per manufacturers’ procedures. Be sure to follow any and all instructions that come with the replacement air conditioning compressor.

8) Apply a vacuum to the car ac system. A minimum of 29 inches of mercury for one hour to insure moisture and residual flushing solids or boiled from the system.

9) Improper refrigerant charges are another major cause of premature failure of car ac compressors and poor system performance.

10) When you’re finished with your repairs conduct a complete system performance test. Each component in the system must be evaluated.

Many compressor malfunctions are the result of another failed component within the system. Failure to diagnose additional problems can cause the new unit to fail again.

Condenser and combination radiator fan motors are components that can cause these failures, because of high system pressures. When these fans malfunction the AC compressor is pushing against pressures much higher than normal conditions.