GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 44244 CNG Tank Support Harness

    Important: CNG Tank cleaning is only necessary when a part such as the high pressure lock-off solenoid has failed due to fuel contamination or when excess water accumulation, that may reduce fuel capacity, is suspected within the tank.

  1. Perform the Fuel Pressure Relief .
  2. Perform the Fuel Tank Venting .
  3. Perform the high pressure lock-off (HPL) removal procedure leaving the HPL installed into the tank finger-tight. Refer to High Pressure Lock-Off Solenoid Replacement .

  4. Object Number: 741161  Size: SH
  5. Place the J 44244 (1) on the shop floor.
  6. Lower the CNG fuel tank (2) on top of the J 44244 (1).
  7. Place the J 44244 support flap so that the HPL  (3) protrudes through the flap.
  8. Place the J 44244 (1) straps around the CNG fuel tank placing the end strap over the HPL (3) and around the neck of the CNG fuel tank.

  9. Object Number: 741163  Size: SH
  10. Securely fasten the J 44244 straps (2) around the CNG fuel tank (1). Longer CNG fuel tanks will require the use of all the J 44244 straps.
  11. Connect the J 44244 to a suitable lifting device.

  12. Object Number: 741165  Size: SH
  13. Slowly raise the CNG fuel tank (1) until the HPL  (2) is above the ground ensuring that the HPL does not contact the floor during the lifting process.
  14. Place a container (3) underneath the HPL (2) in order to collect any drained fluids.
  15. Remove the HPL (2), allowing any fluids to drain completely from the CNG fuel tank.
  16. Dispose of any collected fluids in a safe and approved manner.
  17. Flush the inside of the CNG fuel tank using clean water.
  18. Dry the inside of the CNG fuel tank using compressed air.
  19. Install the HPL (2) finger-tight.

  20. Object Number: 741163  Size: SH
  21. Slowly lower the CNG fuel tank (1) back to the ground ensuring the HPL does not contact the ground.

  22. Object Number: 741161  Size: SH
  23. Remove the J 44244 (1) from the CNG fuel tank (2).
  24. Complete the installation of the HPL into the tank and the tank into the vehicle by completing the installation steps as indicated in the High Pressure Lock-Off Solenoid Replacement .