GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 1855726  Size: SH
  1. Block the wheels.
  2. Drain all of the air reservoirs. Refer to Air Brake Reservoir Draining.
  3. Mark the air lines and connections in order to aid in installation.
  4. Disconnect the park brake indicator switch electrical connector (1).
  5. Disconnect the rear axle differential lock switch electrical connector (2), if equipped.

  6. Object Number: 1855728  Size: SH

    Important: Do not disconnect the air lines from the air brake application valve.

  7. Disconnect the air lines from the air brake supply manifold (1). Refer to Hose and Line Replacement - Nylon Push-In Type Fitting.
  8. Remove the 2 air brake supply manifold nuts (2).

  9. Object Number: 1855730  Size: SH
  10. From inside the vehicle, disconnect the park brake control valve air lines (1) and the air brake pressure gage air lines from the air brake supply manifold. Refer to Hose and Line Replacement - Nylon Push-In Type Fitting.
  11. Remove the air brake supply manifold.

Installation Procedure


    Object Number: 1855730  Size: SH
  1. From inside the vehicle, connect the park brake control valve air lines (1) and the air brake pressure gage air lines to the air brake supply manifold. Refer to Hose and Line Replacement - Nylon Push-In Type Fitting.
  2. Install the air brake supply manifold.
  3. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1855728  Size: SH
  4. Install the 2 air brake supply manifold nuts (2).
  5. Tighten
    Tighten the nuts to 5 N·m (44 lb in).

  6. Connect the air lines to the air brake supply manifold (1). Refer to Hose and Line Replacement - Nylon Push-In Type Fitting.

  7. Object Number: 1855726  Size: SH
  8. Connect the park brake indicator switch electrical connector (1).
  9. Connect the rear axle differential lock switch electrical connector (2), if equipped.
  10. Start the engine.
  11. Charge the system air pressure to the governor cut-out point.
  12. Stop the engine.
  13. Check for air leaks using a soap solution.
  14. Remove the wheel blocks.