Fuel Pressure Relief Valve: Service and Repair

Compressed Natural Gas Fuel Pressure Relief (With CH-48027)

Special Tools

CH-48027 - Digital Pressure Gauge

For equivalent regional tools, refer to Special Tools Tools and Equipment.

1. Remove the aft and cargo tank covers. Refer to Compressed Natural Gas Tank Cover Replacement - Aft Tank Compressed Natural Gas Tank Cover Replacement - Aft Tank and Compressed Natural Gas Tank Cover Replacement - Cargo Tank Compressed Natural Gas Tank Cover Replacement - Cargo Tank.





2. Close all manual shut-off valves to service the tanks.

3. Remove the engine cover, if required. Refer to Engine Cover Replacement Service and Repair.

Caution:
Clean all of the following areas before performing any disconnections in order to avoid possible contamination in the system:

* The fuel pipe connections

* The hose connections

* The areas surrounding the connections

4. Attempt to start the vehicle. The engine may start for a second or two.

5. The high pressure side of the high pressure regulator will contain approximately 200 PSIG.

6. Open the fuel line connections slowly to relieve the residual pressure.

7. If servicing the low side pressure of the HPR, use the CH-48027 - gaugeto relieve the remaining pressure.