Notice: 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 Draining Reservoirs .
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.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

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.