Servicing the CNG System

Observe the following safety precautions when servicing natural-gas-powered vehicles:

• Before making non-CNG system repairs on a CNG vehicle, close the shutoff valve at the outlet of the CNG container, and keep it closed throughout the repair procedure. Have the CNG system checked by a qualified technician before reopening the fuel shutoff valve.

• Allow only qualified technicians trained in automotive CNG system repair to perform repairs.

• Close the fuel shutoff valve(s) before performing maintenance and repairs, and when storing the vehicle inside. Open the valve(s) only if natural gas is needed to operate the engine or to check for leaks.

• Vent the gas outdoors to a safe location.

• Always use a natural gas detector to test the system for leaks, whether an odor is present or not. Commercial compressed natural gas normally contains an odor-producing chemical to enable users to detect leaks by smell. But because the odor-producing chemical can fade, a leak detector is necessary.

• Routinely inspect the fuel tanks, the fuel filtering and regulating mechanisms, and the fuel lines. Use a natural gas detector to check for any leaks. A soap-and-water solution can be used to pinpoint the exact location of leaks. Replace leaking fuel tanks; repair or replace any lines, devices, or connections that are leaking.

• Always tighten fasteners and fuel connections to the required torque specification, since overtightening or undertightening could cause gas leakage. Tightening to the correct torque specification is critical to the system.