Removal (High Pressure)
- Remove fuel tank cover from trunk. Relieve CNG fuel system pressure. See FUEL SYSTEM PRESSURE RELEASE . Disconnect negative battery cable. Remove tank vent cover nuts and cover. Disconnect 3 electrical connectors from High Pressure Lock-Off (HPL) solenoid. See Figure.
- Loosen fill valve boot clamp and peel back boot. Disconnect fill line at fill valve. Loosen clamp at tank vent boot and peel back boot to expose the union. Disconnect fill line at HPL and remove the line. Disconnect HPL to High Pressure Regulator (HPR) fuel line at the HPL. Disconnect pressure relief device line at HPL.
- Remove trunk trim panel, cargo net, cargo net knobs and left wheel well carpet. Remove fuel fill line from fill valve to the union. Lower rear seat and loosen vent hose clamps at tank and HPR.
- Pull vent hose from HPR. Disconnect HPL to HPR fuel line at HPR. Disconnect pressure relief device line from the HPR mounting ring. Remove lines and vent hose as an assembly. See Fig 1.
WARNING: When venting a Compressed Natural Gas (CNG) fuel tank, take the following precautions to prevent fire and personal injury:
- Use proper grounding procedure to an earth ground to prevent a build-up of static electricity, which can lead to an electrical discharge.
- Use CNG Tank Vent Kit (J 42435) with a vent stack.
- Vent CNG fuel tank in a well ventilated work area.
- Keep sparks, flames, and smoking material away from vent area.
- Wear appropriate hearing protection during venting procedure. A sudden pressure loss from an uncontrolled gas leak can cause hearing damage.
NOTE: The manual valve opening tool can damage main seat of High Pressure Lock-off (HPL) solenoid if used improperly. Use this tool only when HPL is not in operation. - Remove Fuel Pressure Sensor (FPS) from HPL and discard "O" ring. Install fitting and cap in FPS port. Install cap on fuel inlet fitting Leave relief port open. See Fig 2. Connect vent hose to fuel outlet fitting and to vent stack. Connect ground strap (attached to vent hose) to HPL and vent stack ground.
- Before removing manual shut-off fitting from HPL, ensure manual lock-down screw is opened (fully seated counter-clockwise) and that no CNG is venting through vent line. Remove manual shut-off fitting from HPL. Before installing manual vent tool, count number of turns required to rotate tool from fully retracted to fully extended. When venting CNG tank ensure you rotate tool same number of turns. This will ensure HPL pilot valve is un-seated and tank is vented. Some pressure should always vent from CNG tank. Verify manual vent tool is in non-venting position with Allen screw fully seated counter-clockwise. Install manual vent tool into HPL port. See Fig 3.
- Slowly turn manual vent tool Allen screw clockwise until natural gas begins to vent. Allow CNG fuel tank to vent until pressure gauge reads 0 psi (0 kPa). If tank stops venting and pressure is indicated on gauge, check for frozen vent line fitting. If frozen, fitting will eventually thaw and fuel continue to vent. Do not leave tank unsupervised while venting.
- After tank is completely vented, disconnect vent hose from HPL. Remove manual vent tool and all fittings. Remove fuel inlet fitting from HPL and discard "O" rings. Remove fuel outlet fitting from HPL and discard "O" rings. Remove HPL pressure relief device fitting from HPL and discard "O" rings. Using Crowfoot (J 43602), loosen HPL. See Fig 4.
- Remove spare tire bracket. Mark CNG tank in 2 places, approximately 180 degrees apart for reference. Remove tank strap nuts and bolts. Remove clevis and bridge pins. Remove tank straps. Position CNG Tank Restrainer (J 43133) into tank strap bolt holes. See Fig 5.
- Loop restrainer straps around tank and secure straps to the tool. Pull back restrainer to pull tank free from bracket. Pull back on straps to roll tank to upper level of restrainer. Use a lifting device and CNG Tank Lifting Apparatus (J 42309-B) to remove tank from vehicle. See Fig 5. Unscrew and remove HPL and "O" ring from tank. Check inside of tank for debris or excess water accumulation. Clean fuel tank if necessary.