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 rear head ports and the front head compressor drain bolt hole of the REMOVED compressor.

  1. Remove the compressor crankcase oil drain bolt and drain the refrigerant oil from the crankcase and rear head ports into a clean, graduated container.

  2. Object Number: 821777  Size: SH
  3. Rotate the compressor shaft to assist in draining the compressor.
  4. Measure and record the amount of oil drained from the removed compressor.
  5. This measurement will be used during installation of the replacement compressor.

  6. Inspect oil drained from removed compressor. Refer to Air Conditioning Compressor Oil Diagnosis .
  7. Properly discard the used refrigerant oil.
  8. Clean the graduated cylinder.
  9. Important: Drain and measure as much of the refrigerant oil as possible from the rear head ports and the front head compressor drain bolt hole of the NEW compressor.

  10. Remove the compressor crankcase oil drain bolt and drain the refrigerant oil from the crankcase and rear head ports into a clean, graduated container.
  11. Rotate the compressor shaft to assist in draining the compressor.

Balancing Procedure


    Object Number: 1312039  Size: SH

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

    The replacement compressor is shipped with the total system capacity of refrigerant oil.

  1. Refer to the amount of refrigerant oil recorded during the compressor removal.
  2. If the amount of oil recorded from the removed compressor is less than or equal to 75 ml (2.5 fl. oz), add 75 ml of the new PAG oil back into the new compressor through the compressor oil drain bolt hole.
  3. If the amount of oil recorded from the removed compressor is greater than 75 ml (2.5 fl. oz), add the equivalent amount of the new PAG oil back into the new compressor through the compressor oil drain bolt hole.
  4. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  5. Install the compressor oil drain bolt.
  6. Tighten
    Tighten the bolt to 15 N·m (11 lb ft).

  7. Rotate the clutch driver three times to lubricate the internal compressor components.
  8. Important: If additional A/C components are replaced during compressor replacement, add the PAG oil directly to the A/C compressor to compensate the A/C system.

  9. If necessary, refer to Refrigerant System Capacities .