GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

  1. Apply the parking brake.
  2. Block the wheels.
  3. Drain all the reservoirs. Refer to Air Brake Reservoir Draining .

  4. Object Number: 201579  Size: SH
  5. Remove the trailer air brake service coupling at the trailer air brake coupling stud.

Installation Procedure


    Object Number: 201579  Size: SH

    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.

  1. Install the trailer air brake coupling at the trailer air brake coupling stud.
  2. Tighten

        • Tighten the trailer air brake coupling to 35 N·m (26 lb ft).
        • Tighten the trailer air brake coupling stud nut to 45 N·m (33 lb ft).

    Start the engine.

  3. Charge the air system to the governor cut-out point.
  4. Use a soap solution in order to inspect for leaks.
  5. Leakage is not permissible.
  6. Remove the wheel blocks.