GM Service Manual Online
For 1990-2009 cars only

Object Number: 227991  Size: SH

At the rear shock absorbers, the air tube connectors are held on with spring clips which snap into the grooves of the shock absorber air fittings. Air tube connectors are sealed using 2 O-rings.

Important: Before disconnecting any air tube, clean the connector and the surrounding area to prevent dirt and other foreign material from entering the automatic level control system.

To disconnect an air tube from a shock absorber, rotate the spring clip 90 degrees out of the slots, and pull the connector from the shock absorber.

Important: Ensure that the air tube is routed correctly and all fasteners are used.

To connect an air tube to a shock absorber, lubricate the two O-rings using silicone lubricant, rotate the spring clip 90 degrees into the slots, and push the air tube connector on the shock absorber fitting until spring clip snaps into the fitting groove.

Removal Procedure

  1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.

  2. Object Number: 316581  Size: SH
  3. Remove the automatic level control air tube from the automatic level control air dryer.
  4. Remove the bolt and the harness tie from the automatic level control air compressor bracket.

  5. Object Number: 299651  Size: SH
  6. Disconnect the automatic level control air tube from the left and right rear shock absorbers.
  7. Remove the 2 metal clips from the automatic level control air tube and the vehicle.
  8. Remove the automatic level control air tube with the 3 clips from the vehicle.

Installation Procedure


    Object Number: 316581  Size: SH
  1. Connect the automatic level control air tube to the automatic level control air dryer.
  2. 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.

  3. Install the automatic level control air tube with the harness tie and the bolt on the automatic level control air compressor bracket.
  4. Tighten
    Tighten the automatic level control air tube to air compressor bracket bolt to 4 N·m (35 lb ft).


    Object Number: 299651  Size: SH
  5. Install the automatic level control air tube on the vehicle with three clips.
  6. Connect the air tube to the left and right rear shock absorbers.
  7. Install two metal clips on the air tube and the vehicle. Place each clip immediately forward of the wheel house fold-over tabs on the LH and RH side of the vehicle.
  8. Important: Before driving the vehicle, turn the ignition on and wait approximately 45 seconds. This will permit the automatic level control system to execute the Air Replenishment Cycle, ensuring that the air adjustable shock absorbers are filled with residual pressure.

  9. Lower the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.