Trailer Brake Supply Valve Leakage Test for Isuzu Isuzu MD Steel Tilt (F Model) 2000

1. Block the wheels.
2. Start the engine.
3. Charge the system air pressure to the governor cut-out point.
4. Pull out the trailer air supply knob.
5. Pull out the system park knob.
6. Apply a soap solution to the exhaust vent and around the base of the trailer air supply knob.
7. Verify that leakage is less than a 25 mm (1 in) bubble in 5 seconds. If not, replace the valve.
8. If the leakage exceeds these limitations, replace the valve.
9. Push in the trailer air supply knob.
10. Apply a soap solution to the exhaust port.
11. Check that the leakage is less than a 25 mm (1 in) bubble in 5 seconds.
12. If the leakage exceeds these limitations, replace the valve.
13. Set the parking brake.
14. Remove the wheel blocks.