• | J 43602 HPL Crowfoot - 2.5 inch |
• | J 45529 Tank Removal Tool |
• | J 45878 Combustible Gas Detector |
Caution: Do not install this part if you can not completely refill the vehicle with CNG after a repair. Failure to properly leak-check the system after the part replacement may result in serious injury, death, or damage to the vehicle or the part.
Caution: Always use the J 42435-B Compressed Natural Gas (CNG) Fuel Tank Venting Kit in conjunction with the General Motors approved Fuel Tank Venting service procedure to vent CNG fuel tanks. Failure to use the J 42435-B and follow the approved Fuel Tank Venting procedure could result in death, serious injury or vehicle and component damage.
The J 42435-B is required for the following reasons:• | Natural gas fuel vapor can also contain water vapor. |
• | The pressure drop associated with venting high pressure gaseous fuel can cause fuel vapor, tank and line temperatures to reach -73°C (-100°F) or colder. |
• | The below freezing temperature can cause the water vapor to freeze |
• | The J 42435-B vent hose contains an orifice which is intended to freeze before the CNG high pressure lock-off (HPL) tank valve freezes. |
• | The J 42435-B pressure gauge can indicate a restricted orifice if fuel flow ceases. |
• | Internal fuel tank ice build-up may result when venting the CNG fuel tank without the J 42435-B. |
- | Internal fuel tank ice build-up can completely restrict the venting of fuel. |
- | Venting may cease indefinitely depending upon ambient temperature conditions. |
- | The ceasing of fuel tank venting may falsely indicate that the fuel tank pressure has been completely vented. |
- | CNG fuel tanks with exceptionally high water content are suceptible to internal fuel tank ice build-up even with the use of the J 42435-B. |
If the ambient temperature is less than 7°C (45°F), warm the fuel tank and vent line assembly manually, either with warm water or by placing the tank and line assembly into a warm environment. |
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.
Proceed directly to Step 27 for vehicles equipped with the ZW9 option.
Important: Do not hold the HPR using the HPR cover hex flange. As required wedge a wrench between the HPR and the tank frame in order to keep the HPR from spinning in the 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.
Do not install the fuel line fittings.
Proceed directly to Step 9 for vehicles equipped with the ZW9 option.
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.
Tighten
Tighten the tank strap mounting bolts to 47 N·m (35 lb ft).
Tighten
Tighten the HPL to a nominal torque of 305 N·m (225 lb ft) at 0 degrees. You must compensate for the torque wrench and the HPL crowfoot offset. Refer to the formula below for compensation of your
torque wrench.
Important: Ensure the J 43602 is straight on the torque wrench.
• | Multiply your torque wrench length in inches by 305 (225). |
• | 18 inch torque wrench example: 18 X 305 = 5490. |
• | Add 3 to the length of your torque wrench. |
• | 18 inch torque wrench example: 18 + 3 = 21. |
• | Divide the first value obtained by the second value obtained. The result indicates the amount of torque your wrench should tighten the HPL to. |
• | 18 inch torque wrench example: 5490 divided by 21 = 261.4. |
• | For an 18 inch long torque wrench tighten the HPL to 261.4 N·m. |
Tighten
Tighten the fitting to 48 N·m (35 lb ft).
Tighten
Tighten the sensor to 27 N·m (20 lb ft).
Tighten
Tighten the tank strap mounting bolts to 47 N·m (35 lb ft).
Tighten
Tighten the line fitting to 37 N·m (27 lb ft).
Tighten
Tighten the line fitting to 37 N·m (27 lb ft).
Tighten
Tighten the bolts to 50 N·m (37 lb ft).
Important: Do not hold the HPR using the HPR cover hex flange. As required wedge a wrench between the HPR and the tank frame in order to keep the HPR from spinning in the bracket.
Tighten
Tighten the nut to 54 N·m (40 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.
Tighten
Tighten the fuel line fitting to 48 N·m (35 lb ft).
Tighten
Tighten the bolts (1) to 27 N·m (20 lb ft).
Tighten
Tighten the fitting to 37 N·m (27 lb ft).
Tighten
Tighten the bolts to 8 N·m (71 lb in).
Caution: The high pressure lock-off solenoid seal is more likely to leak at a lower fuel pressure. Always perform the fuel leak procedure exactly as specified. Failure to follow the proper procedures may result in serious injury or damage to the vehicle or part.
31.1. | 3 447 kPa (500 psi) |
31.2. | 10 342 kPa (1,500 psi) |
31.3. | 20 684 kPa (3,000 psi) |