How to Install BBK Liquid-Filled Fuel Pressure Gauge on your Mustang

Step 1: Disconnect negative battery terminal and relieve any pressure in the fuel system by carefully depressing the plunger in the fuel line Schrader valve. This valve, which is similar to a tire’s valve stem, will be located either on the fuel injector rail or on the steel hard lines directly before the fuel injector rail.

Step 2: Once system pressure is relieved, simply unscrew the entire valve assembly from the line. This valve will no longer be needed as the pressure gauge adapter fitting will replace it.

Step 3: Carefully thread the brass adapter fitting in until a snug fit with a wrench is achieved. The threads are self-sealing tapered, therefore, teflon tape should not be necessary. To avoid cracking the fuel line use a second wrench on the hex portion of the fuel line if applicable.

Step 4: Simply thread in the pressure gauge and tighten snugly into the brass adapter making a note of the position of the gauge face. The tapered threads can usually be tightened slightly more to orientate the face of the gauge, however, you may never loosen the thread at all or a fuel leak is guaranteed.

Step 5: Reconnect the battery and turn ignition key on, observe to be sure that no leaks are present and that the gauge is properly functioning. Periodic inspections should be done to ensure no fuel leaks have formed.