GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 1999 🢒 Isuzu MD Steel Tilt (F Model) 🢒 Brakes 🢒 Air Brakes 🢒 Air Brake Park Control Valve Operational Check

Air Brake Park Control Valve Operational Check Operational Check

  1. Block the wheels.
  2. Start the engine.
  3. Charge the system to the air compressor governor cut-out point.
  4. Stop the engine.

    5. Object Number: 227847 Size: MH
  5. Pull out the park control valve (cab mounted) knob and release the brake pedal.
  6. Verify that the spring brake chamber assemblies are applied.
  7. Push in the park control valve (cab mounted) knob.
  8. Verify that the spring brake chamber assemblies are fully released.
  9. Drain the front service air reservoir.
  10. Observe the dual air pressure gauge while the rear air reservoir is draining.
  11. Verify that the park control valve (cab mounted) pops out when the air pressure drops below 276 kPa (40 psi) on models without trailer provisions.

    12. For models with trailer provision, refer to Parking Control Valve Operational Check

    If the park control valve knob does not pop out, overhaul or replace the park control valve (cab mounted).

  12. Remove the wheel blocks.

Air Brake Park Control Valve Operational Check Leakage Test

  1. Block the wheels.
  2. Start the engine.
  3. Charge the system to the air compressor governor cut-out point.
  4. Stop the engine.
  5. Pull out the park control valve (cab mounted) knob and release the brake pedal.
  6. Inspect the exhaust port for air leakage. The air leakage should not exceed 25.4 mm (1 in) bubble in 5 seconds.

    7. If air leakage is excessive, overhaul or replace the park control valve (cab mounted).

  7. Inspect the plunger stem for air leakage. The air leakage should not exceed 25.4 mm (1 in) bubble in 5 seconds.

    8. If air leakage is excessive, overhaul or replace the park control valve (cab mounted).

  8. Inspect the upper and lower valve body for air leakage.

    9. No air leakage should occur between the upper and lower valve body. If air leakage occurs, overhaul or replace the park control valve (cab mounted).

  9. Push in the system park knob.
  10. Inspect the exhaust port for air leakage. Air leakage should not exceed a 25.4 mm (1 in) bubble in 3 seconds.

    11. If air leakage is excessive, overhaul or replace the park control valve (cab mounted).

  11. Inspect the plunger stem for air leakage. Air leakage should not exceed a 25.4 mm (1 in) bubble in 3 seconds.

    12. If air leakage is excessive, overhaul or replace the park control valve (cab mounted).

  12. Remove the wheel blocks.