GM Service Manual Online
For 1990-2009 cars only

Refer to Air Compressor Governor Valve Specifications for the correct governor settings.

Adjustment may be needed if the range falls below 100 kPa (15 psi) of the recommended pressures or if the pressure settings are incorrect. Inspect for restrictions of the following components prior to adjustment:

    • The air filter element
    • The government inlet hose LG5
    • The air compressor air strainer filter LP4/L21

Proceed as follows once the check for restrictions is completed:


    Object Number: 200542  Size: SH
  1. Remove the governor cover from the governor.

  2. Object Number: 200545  Size: SH
  3. Loosen the adjusting screw locknut.
  4. Important: 

       • Be careful to not over-adjust. Each 1/4 turn of the adjusting screw locknut raises or lowers the pressure settings approximately 28 kPa (4 psi).
       • The pressure range between the cut-in and the cut-out setting is not adjustable.

  5. Turn the adjusting screw counterclockwise to raise the pressure setting.
  6. Turn the adjusting screw clockwise to lower the pressure setting.
  7. Tighten the adjusting screw locknut after the adjustment.
  8. Recheck the cut-in and cut-out pressures. Refer to Air Compressor Governor Valve Specifications .

  9. Object Number: 200542  Size: SH
  10. Install the governor cover on the governor.