The factory recommended fuel pressure relief procedure requires the use of a hose with a special fitting that threads onto the pressure test port (also called a Schrader Valve and looks similar to a tire valve stem) on the fuel rail. This type of tool usually has a pressure gauge as part of the tool so it can also be used to test the fuel system pressure. Although this special tool is available at automotive tool stores and it is recommended, it may also be possible to use a small screwdriver to depress the valve, allowing the fuel to run out onto a shop cloth. Use care and wear eye protection. The system normally operates at about 45 psi.
- Disconnect the negative battery cable to avoid possible fuel discharge if an accidental attempt is made to start the engine.
- Remove the cosmetic/acoustic engine cover.
- Loosen the fuel filler cap to relieve the fuel tank vapor pressure.
- GM recommends their tool J 34730-1A, or equivalent, be used. Attach the tool to the fuel pressure connection. Wrap a shop cloth around the fuel pressure connection while connecting the fuel pressure hose fitting to avoid spillage. This tool has a bleed hose that should be placed in an approved container to catch the fuel the will be expelled when the valve is opened.
- Open the valve to bleed the fuel system pressure. The fuel connections are now safe for servicing.
- Drain any fuel remaining in the tool into an approved container.