Installation Procedure (1998 Models)
Tools Required^ J 43602 HPL Crowfoot
^ J 42309 CNG Tank Sling
^ J 41416 Ultrasonic Leak Detector
1. Install a NEW O-ring on the HPL.
2. Lubricate the O-ring with petroleum jelly.
3. Install the HPL in the tank and tighten hand-tight.
4. Lower the tank onto the lower mounting brackets using a lifting device and the J 42309 CNG Tank Sling.
5. Roll the tank to the proper position using the orientation marks.
6. Verify that the distance between the tank (1) and the pickup box (2) is within specification.
7. Verify that the FPS (4) is positioned as shown.
8. Install the upper mounting brackets.
Important:
^ Verify that the bridge pins do not contact the CNG fuel tank.
^ Verify that the rubber isolators are correctly positioned before tightening the upper mounting bracket fasteners.
9. Install the bridge pins and clevis pins to the upper mounting brackets.
10. Install the OLD mounting bracket nuts and bolts.
Tighten
Tighten the OLD mounting bracket nuts to 47 N.m (35 lb ft)
11. Tighten the HPL as specified.
Tighten
Tighten the HPL to a nominal torque of 305 N.m (225 lb ft) at 0 degree. Refer to the formula below for compensation of your torque wrench.
Important:
Ensure the J 43602 HPL Crowfoot removal tool is straight (0 degree) on the torque wrench.
To obtain your Dial reading, perform the following steps:
11.1. Multiply your torque wrench length in inches by 305 (225)(1).
11.2. Add three to the length of your torque wrench(2).
11.3. Divide the first value(1) obtained by the second value(2) obtained. The result(3) will indicate the amount of torque your wrench should tighten the HPL to.
For example if your wrench were 18 inches long:
18 X 305 5490(1)
18 + 3 = 21(2)
54901(1) divided by 21(2) = 261(3)
You would tighten the HPL to 261 N.m (192 lb ft).
12. Remove the OLD mounting bracket nuts and bolts and discard them.
13. Verify that the distance between the tank (1) and the pickup box (2) is within specification.
14. Verify that the FPS (4) is positioned as shown.
15. Install NEW mounting bracket bolts and nuts.
Tighten
Tighten the mounting bracket nuts to 47 N.m (35 lb ft).
16. Install the fuel outlet fitting (3) into the HPL using a NEW O-ring. Lubricate the O-ring with petroleum jelly.
Tighten
Tighten the fitting to 27 N.m (20 lb ft).
17. Install the fuel inlet fitting (1) into the HPL using a NEW O-ring. Lubricate the O-ring with petroleum jelly.
Tighten
Tighten the fitting to 48 N.m (35 lb ft).
18. Install the FPS (2) into the HPL using a NEW O-ring. Lubricate the O-ring with petroleum jelly.
Tighten
Tighten the fitting to 27 N.m (20 lb ft).
19. Connect the fuel line (1) and the fill line (2) using NEW O-ring face seals. Lubricate the O-rings with petroleum jelly.
Tighten
^ Tighten the fuel line fitting to 24 N.m (18 lb ft).
^ Tighten the fill line fitting (2) to 37 N.m (27 lb ft).
20. Connect the following connectors:
^ High pressure lock-off (HPL) (1)
^ Fuel temperature sensor (FTS) (2)
^ Fuel pressure sensor (FPS) (3)
Caution:
The high pressure lock-off solenoid seal is more likely to leak at a lower pressure. Always perform the fuel leak procedure exactly as specified. Failure to follow the proper procedures may result in serious personal injury or damage to the vehicle or part.
21. Fuel the vehicle in three stages at the following pressures:
21.1. 3,447 kPa (500 psi)
21.2. 10,342 kPa (1500 psi)
21.3. 20,685 kPa (3000 psi)
22. Using the J 41416 Ultrasonic Leak Detector, inspect for fuel leaks at the HPL at EACH pressure.
23. Connect the negative battery cable.
24. Start and operate the engine on CNG.
25. Inspect for fuel leaks at each serviced fitting using the J 41416.
26. Attach the information label supplied with the replacement HPL in a visible location on the head of the tank.
27. Install the tank cover. Refer to CNG Fuel Tank Cover Replacement procedure in the Body Rear End subsection of the Bi-Fuel Supplement Service Manual.