Trailer Coupling Hose and Line Bracket Replacement for GMC Truck TopKick C-Series (Conventional) C4/C5 2005

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 emergency coupling hose. Refer to Hose and Line Replacement - Trailer and Emergency .
5. Remove the trailer air brake service brake coupling hose. Refer to Hose and Line Replacement - Trailer and Emergency .
6. Remove the trailer air brake coupling hose bracket connectors and the nuts.



7. Remove the trailer air brake coupling hose bracket bolts, washers and the bracket.

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 coupling hose bracket, the washers, and the bracket bolts.

Tighten

•	Tighten the trailer air brake coupling hose bracket bolts to 12 N·m (106 lb in).

•	Tighten the trailer air brake coupling hose bracket lower connectors to 28 N·m (21 lb ft).

•	Tighten the trailer air brake coupling hose bracket connector nuts to 12 N·m (106 lb in).

Install the trailer air brake service brake coupling hose.

2. Install the trailer air brake emergency brake coupling hose.
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.