Tools Required

J 45878 Combustible Gas Detector

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. Disconnect the low pressure lock-off (LPL) solenoid electrical connector (5).
4. Disconnect the fuel inlet line (1) from the LPL fitting (2).



5. Remove the intermediate pressure regulator (IPR) fuel outlet line hold-down nut (6).
6. Remove the fuel outlet line hold down (4).
7. Disconnect the IPR fuel outlet lines (5, 8) from the IPR (2).



8. Remove the IPR/LPL bracket nuts (3).
9. Remove the IPR/LPL assembly from the vehicle.



10. Remove the bolts (3) that retain the IPR/LPL assembly (1, 4) to the bracket (2).



11. While holding the line union (2) rotate and remove the IPR (3) or the LPL (1) as required.

Important: Apply pipe thread sealant with Teflon® to the threads of the line union (2). Do not use Teflon® tape.

1. While holding the line union (2) rotate and install the IPR (3) or the LPL (1) as required.

Tighten
Tighten the IPR or LPL hand tight plus one to three turns as required to align the IPR/LPL assembly to 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.

2. Install the IPR/LPL assembly (1, 4) to the mounting plate (2) using the attaching bolts (3).

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




3. Install the IPR/LPL bracket (4) to the engine (2) using the attaching nuts (3).

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




4. Connect the IPR fuel outlet lines (5, 8) to the IPR (2) using new O-rings (3). Lubricate the O-ring with petroleum jelly.
5. Install the line hold-down bracket (4) and nut (6).

Tighten
Tighten the nut to 9 N·m (80 lb in).




6. Connect the LPL electrical connector (5).

Connect the fuel inlet line (1) to the LPL fitting (2) using a new O-ring face seal. Lubricate the O-ring with petroleum jelly.

Tighten
Tighten the fitting 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 the serviced fitting using the J 45878 or an equivalent liquid leak detector.