Tools Required

J 41416

Caution: Natural gas is highly flammable. In order to reduce the risk of fire and personal injury, keep sparks, flames, and smoking materials away from the vehicle while you perform the Compressed Natural Gas (CNG) fuel system service.

Caution: The Compressed Natural Gas (CNG) system operates at pressures up to 24820 kpa (3600 psi). Relieve the CNG fuel system pressure before servicing CNG fuel system components in order to reduce the risk of fire and personal injury.

1. Relieve the fuel system pressure. Refer to Fuel Pressure Relief .

Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical in the C/K Pickup service manual.



3. Remove the tank cover (2). Refer to Fuel Tank Cover Replacement .



4. Disconnect the fill line (6) from the check valve (5).



5. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information in the C/K Pickup service manual.
6. Disconnect the fill line (3) from the fill valve (2).
7. Remove the fill line from the vehicle.

Caution: Natural gas is stored under high pressure. If a leak occurs, the high pressure could cause a personal injury. In order to prevent Compressed Natural Gas (CNG) fuel leaks, always replace the CNG fuel system O-rings during service.




1. Install the fill line into the vehicle.
2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information in the C/K Pickup service manual.
3. Connect the fuel fill line (3) to the fill valve (2) using a new O-ring. Lubricate the O-ring with petroleum jelly.

Tighten
Tighten the fitting to 37 N·m (27 lb ft).

4. Lower the vehicle.



5. Connect the fuel fill line (6) to the check valve fitting (5) using a new O-ring face seal. Lubricate the O-ring face seal with petroleum jelly.

Tighten
Tighten the fitting to 24 N·m (18 lb ft).

Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

6. Install the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical in the C/K Pickup service manual.
7. Start the vehicle and inspect for CNG fuel leaks at the serviced fittings using the J 41416 or an equivalent liquid leak detector.



8. Install the tank cover (2). Refer to Fuel Tank Cover Replacement .