Fuel Hose/Pipe Replacement - Filter to High Pressure Regulator Pickup

Tools Required

J 45878 Combustible Gas Detector

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 line at the fuel filter outlet (2).
5. Disconnect the fuel line hold down clips (3).



6. Disconnect the fuel line (3) from the high pressure regulator (HPR) (1) inlet fitting.
7. Remove the line from the vehicle.

1. Install the line into 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.

2. Connect the line (3) to the high pressure regulator (HPR) (1) inlet fitting using a new O-ring face seal. Lubricate the O-ring with petroleum jelly.

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




3. Connect the fuel line to the fuel filter outlet fitting (2) using a new O-ring. Lubricate the O-ring face seal with petroleum jelly.

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

4. Install the fuel line hold down clips (3).

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.

5. Install the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical in the C/K Pickup Service Manual.
6. Start the vehicle and inspect for CNG fuel leaks at all serviced fittings using the J 45878 or an equivalent liquid leak detector.



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

Fuel Hose/Pipe Replacement - Filter to High Pressure Regulator Cab/Chassis

Tools Required

J 45878 Combustible Gas Detector

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 truck body as required on ZW9 equipped vehicles in order to gain access to the CNG fuel tank.



4. Disconnect the fuel filter inlet line (2).
5. Disconnect the high pressure regulator (HPR) fuel inlet line (3).



6. Remove the fuel filter mounting bolts (1).
7. Remove the fuel filter mounting bracket bolts (2, 4).
8. Remove the fuel filter/line assembly from the vehicle.
9. Observe and record the orientation of the fuel line.
10. Disconnect the fuel filter outlet line from the fuel filter.
11. Remove the fuel line from the filter mounting bracket assembly.

1. Install the fuel line through the hole in the filter mounting bracket.

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.

2. Connect the line to the filter outlet fitting with a new O-ring face seal. Lubricate the O-ring with petroleum jelly.

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

Notice: Refer to Fastener Notice in the Preface section.

3. Install the fuel filter mounting bolts (1).

Tighten
Tighten the bolts to 20 N·m (15 lb ft).

4. Install the fuel filter bracket mounting bolts (2, 4).

Tighten
Tighten the bolts to 12 N·m (9 lb ft).




5. Connect the fuel line to the fuel filter inlet fitting (2) with a new O-ring. Lubricate the O-ring face seal with petroleum jelly.

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

6. Connect the fuel line to the HPR inlet fitting (3) with a new O-ring. Lubricate the O-ring face seal with petroleum jelly.

Tighten
Tighten the fuel line to 37 N·m (27 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.

7. Install the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical in the C/K Pickup Service Manual.
8. Start the vehicle and inspect for CNG fuel leaks at all serviced fittings using the J 45878 or an equivalent liquid leak detector.
9. Install the truck body as required on ZW9 equipped vehicles.