Compressed Natural Gas High Pressure Regulator Replacement Passenger/Cargo

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 CNG fuel system pressure. Refer to the 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 G/H Van Service Manual.



3. Clamp off the coolant hoses using coolant hose pinch pliers.
4. Mark the hoses prior to removal.
5. Remove the hose clamps and hoses from the high pressure regulator coolant fittings (1, 2).



6. Remove the fuel inlet lines (1,4) from the high pressure regulator (3) and discard the O-rings.
7. Remove the fuel outlet line (2) from the filter and discard the copper sealing washer.



8. Remove the mounting bracket bolts (1).
9. Remove the high pressure regulator assembly.

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 high pressure regulator and mounting bracket (2) to the vehicle frame using the mounting bolts (1).

Tighten
Tighten the bolts to 38 N·m (28 lb ft).





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.

Important: Ensure that a clean or new fuel filter, spring and gasket (1) are installed prior to installation of the fuel inlet fitting (3).

2. Install the fuel inlet fitting (3) using a new O-ring. Lubricate the O-ring with petroleum jelly or equivalent.

Tighten
Tighten the fuel inlet fitting to 45 N·m (33 lb ft).




3. Connect the fuel inlet line (1,4) to the fuel inlet fitting using new O-rings. Lubricate the O-ring with petroleum jelly or equivalent.

Tighten
Tighten the fuel inlet line fittings to 45 N·m (33 lb ft).

4. Connect the fuel outlet line (2) to the filter using a new copper sealing washer.

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




5. Install the coolant hoses and clamps to the high pressure regulator coolant fittings (1, 2) as marked during removal.
6. Remove the coolant hose pinch pliers.
7. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical in the G/H Van Service Manual.
8. Prime the CNG fuel system by cycling the ignition ON and OFF several times.
9. Start the engine and use the J 45878 in order to inspect for CNG fuel system leaks at each serviced fitting.
10. Inspect for proper coolant level and fill as necessary.

Compressed Natural Gas High Pressure Regulator Replacement Cutaway

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 CNG fuel system pressure. Refer to the 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 G/H Van Service Manual.



3. Clamp off the coolant hoses using coolant hose pinch pliers.
4. Mark the hoses prior to removal.
5. Remove the hose clamps and hoses from the high pressure regulator coolant fittings (1, 2).



6. Remove the fuel inlet lines (1,4) from the high pressure regulator (2) and discard the O-rings.
7. Remove the fuel outlet line (3) from the filter and discard the copper sealing washer.



8. Remove the mounting bracket bolts (1).
9. Remove the mounting bracket nut (3).
10. Remove the high pressure regulator assembly (2).

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 high pressure regulator and mounting bracket (2) to the vehicle frame using the mounting bolts (1).

Tighten
Tighten the bolts to 38 N·m (28 lb ft).

2. Install the high pressure regulator mounting support bracket nut (3).

Tighten
Tighten the nut to 38 N·m (28 lb ft).





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.

Important: Ensure that a clean or new fuel filter, spring and gasket (1) are installed prior to installation of the fuel inlet fitting (3).

3. Install the fuel inlet fitting (3) using a new O-ring. Lubricate the O-ring with petroleum jelly or equivalent.

Tighten
Tighten the fuel inlet fitting to 45 N·m (33 lb ft).




4. Connect the fuel inlet line (1,4) to the fuel inlet fitting using new O-rings. Lubricate the O-ring with petroleum jelly or equivalent.

Tighten
Tighten the fuel inlet line fittings to 45 N·m (33 lb ft).

5. Connect the fuel outlet line (3) to the filter using a new copper sealing washer.

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




6. Install the coolant hoses and clamps to the high pressure regulator coolant fittings (1, 2) as marked during removal.
7. Remove the coolant hose pinch pliers.
8. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical in the G/H Van Service Manual.
9. Prime the CNG fuel system by cycling the ignition ON and OFF several times.
10. Start the engine and use the J 45878 in order to inspect for CNG fuel system leaks at each serviced fitting.
11. Inspect for proper coolant level and fill as necessary.