GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2003 🢒 TopKick C-Series Commercial (Cutaway) C4/C5 🢒 Brakes 🢒 Air Brakes 🢒 Parking Control Valve Leakage Test
  1. Block the wheels.
  2. Start the engine.
  3. Charge the system air pressure to the governor cut-out point.

    4. Object Number: 209563 Size: SH
  4. Push in the system park knob (1).

    5. Object Number: 209567 Size: SH
  5. Pull out the tractor park knob (1) and release the brake pedal.
  6. Apply a soap solution to the exhaust port.
  7. Check for leakage. Slight leakage is permitted. If leakage is excessive, replace the valve. Refer to Chassis Mount Air Brake Park Control Valve Replacement or overhaul the valve. Refer to Air Brake System Description and Operation .
  8. Push in the tractor park knob (1).
  9. Check for leakage at the exhaust port. Slight leakage is permitted. If leakage is excessive, replace the valve. Refer to Chassis Mount Air Brake Park Control Valve Replacement or overhaul the valve. Refer to Air Brake System Description and Operation .
  10. Set the parking brake.
  11. Remove the wheel blocks.