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. Before draining oil, position the compressor verdically (clutch facing upwards) and let it sit for 1 minute.
  2. Position the compressor horizontally, with the ports facing downward, rotate the clutch and shake the compressor in order to remove as much oil from the compressor as possible.
  3. Drain the oil from both the suction and discharge ports of the removed compressor into a clean, graduated container. Rotate the compressor shaft to assist in draining the compressor.

  4. Object Number: 821777  Size: SH
  5. Measure and record the amount of oil drained from the removed compressor. This measurement will be used during installation of the replacement compressor.
  6. Inspect oil drained from removed comperssor. Refer to Air Conditioning Compressor Oil Diagnosis
  7. Properly discard the used refrigerant oil.

Balancing Procedure

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


    Object Number: 821777  Size: SH
  1. Before installing the compressor, the refrigerant oil will have to be fully drained.
  2. Add back the same quantity of polyalkylene glycol (PAG) oil as drained from the removed compressor.
  3. Refer to the amount of refrigerant oil recorded during the compressor removal.