Caution: When replacing tubing, make sure that the tubing is free of burrs, cuttings, and dirt. While wearing safety glasses, use compressed air to blow out contaminants. Contaminants can destroy the air brake valve sealants.

1. Apply the parking brake.
2. Block the wheels.
3. Drain all the reservoirs. Refer to Air Brake Reservoir Draining.
4. Remove the trailer air brake service and the emergency coupling hose at the trailer air brake hose bracket gladhand.



5. Remove the trailer air brake emergency coupling hose.
6. Remove the trailer air brake service coupling hose.

Caution: Refer to Fastener Caution in the Preface section.




1. Install the trailer air brake service coupling hose.

Tighten
Tighten the trailer air brake service coupling hose to 28 N·m (21 lb ft).

2. Install the trailer air brake service and the emergency coupling hose at the trailer air brake hose bracket gladhand.
3. Start the engine.
4. Charge the system air pressure to the governor cut-out point.
5. Check for leaks with a soap solution.

Leakage is not permissible.

6. Remove the wheel blocks.