GM Service Manual Online
For 1990-2009 cars only

Draining Procedure

    Important: Drain and measure as much of the refrigerant oil as possible from the removed compressor.

  1. Remove the oil drain plug from the compressor crankcase and drain the crankcase into a clean, graduated container.

  2. Object Number: 1342638  Size: SH
  3. Drain the oil from both the suction and discharge ports of the removed compressor into the same container.
  4. Rotate the compressor shaft to assist in draining the compressor.

  5. Measure and record the amount of oil drained from the removed compressor.
  6. This measurement will be used during installation of the replacement compressor.

  7. Inspect the oil drained from removed compressor. Refer to Air Conditioning Compressor Oil Diagnosis.
  8. Properly discard the used refrigerant oil.

Balancing Procedure


    Object Number: 821777  Size: SH

    Important: The refrigerant oil in the A/C system must be balanced during compressor replacement.

  1. The replacement compressor is shipped with 150 ml (5 oz) of refrigerant oil.
  2. Compare the amount of refrigerant oil recorded during compressor removal to the amount of refrigerant oil shipped in the replacement compressor.
  3. If the amount of refrigerant oil drained and recorded from the removed compressor is:

    • Less than 150 ml (5 oz)
       - Refer to the amount of refrigerant oil recorded during compressor removal.
       - Subtract the amount recorded from the replacement compressor capacity. Refer to Refrigerant System Capacities.
       - The difference between the replacement compressor capacity and the recorded amount is the calculated amount to be drained from the replacement compressor.
    • More than 150 ml (5 oz)
    • Add to the compressor the difference between the 150 ml (5 oz) and the amount desired.