Primary Supply Reservoir Safety Valve Operational Check for GMC Truck TopKick C-Series (Conventional) C4/C5 2005
- Apply the parking brake.
- Start the engine.
- Charge the system air pressure to the governor cut-out point.
- Pull out the exposed end of the valve stem.
- Air should be expelled from the vent.
- Replace the safety valve (1) if the air is not expelled.
- Release the valve stem.
- Check that the air exhaust stops.
- Replace or overhaul the safety valve (1) if the air does
not stop. Refer to
Primary Air Brake Supply Reservoir Safety Valve Replacement
or
Air Brake System Description and Operation
.