GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2004 🢒 Park Avenue 🢒 Suspension 🢒 Automatic Level Control 🢒 Air Compressor Replacement

Removal Procedure
  1. Raise the vehicle and suitably support. Refer to Lifting and Jacking the Vehicle .

    2. Important: Before disconnecting the air hose from the intake air filter or the air compressor, clean the components and the surrounding area to prevent dirt and other foreign material from entering the ALC system.


    Object Number: 227996 Size: SH
  2. Disconnect the air tube from the air dryer.
  3. Remove the bolt and the harness tie with the air tube from the air compressor bracket.

    4. Object Number: 227988 Size: SH
  4. Remove the intake air filter from the vehicle.
  5. Remove the vehicle harness connector from the air compressor connector.
  6. Remove the 2 nuts, the bolt, and the air compressor assembly from the vehicle.

    7. Object Number: 227993 Size: SH
  7. Slide the air compressor connector off of the connector anchor.
  8. Remove 2 bolts and the heat shield from the air compressor bracket.

    9. Object Number: 227997 Size: SH
  9. Remove 3 bolts and the air compressor assembly from the bracket.
  10. Remove the air dryer from the air compressor. Refer to Automatic Level Control Air Dryer Replacement .

    11. Object Number: 226931 Size: SH
  11. Remove the air hose from the air compressor at 2 places.

    12. Object Number: 227985 Size: SH
  12. Remove the 2 screws and the 2 brackets from the air compressor.

Installation Procedure

    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.


    Object Number: 227985 Size: SH
  1. Install the 2 brackets on the air compressor with 2 screws.

    2. Tighten
    Tighten 2 screws to 7 N·m (62 lb in).


    Object Number: 226931 Size: SH
  2. Connect the air hose to the air compressor at 2 places.
  3. Install the air dryer on the air compressor. Refer to Automatic Level Control Air Dryer Replacement .

    4. Object Number: 227997 Size: SH
  4. Install the air compressor assembly onto the bracket with 3 bolts.

    5. Tighten
    Tighten 3 bolts to 3 N·m (26 lb in).


    Object Number: 227993 Size: SH
  5. Install the heat shield on the air compressor bracket with 2 bolts (Do not install the third heat shield bolt. It must be installed after the air tube is connected).
  6. Install the air compressor connector to the connector anchor.

    7. Object Number: 227988 Size: SH
  7. Install the air compressor assembly on the vehicle with 2 nuts and a bolt.

    8. Tighten

        • Tighten the bolt to 9 N·m (80 lb in).
        • Tighten 2 nuts to 9 N·m (80 lb in).
  8. Connect the harness connector to the air compressor connector.
  9. Install the intake air filter on the vehicle.

    10. Object Number: 227996 Size: SH
  10. Connect the air tube to the air dryer.
  11. Connect the air tube with the harness tie to the air compressor bracket with the bolt.

    12. Tighten
    Tighten 3 bolts to 4 N·m (35 lb in).

    Important: Before driving the vehicle, turn the ignition on and wait approximately 45 seconds. This will permit the ALC system to execute the ARC, ensuring that the air adjustable shock absorbers are filled with residual pressure.

  12. Lower the vehicle. Refer to Lifting and Jacking the Vehicle .