Ford Aerostar 1986-1997 Repair Guide

Relieving Fuel System Pressure


See Figure 1

All fuel injected engines are equipped with a pressure relief valve located on the fuel supply manifold.

  1. Remove the fuel tank cap.
  3. Attach fuel pressure gauge T80L-9974-A, or equivalent, to the pressure relief valve to release the fuel pressure.

If a suitable pressure gauge is not available, disconnect the vacuum hose from the fuel pressure regulator and attach a hand vacuum pump. Apply 25 in.Hg (84 kPa) of vacuum to the regulator to vent the fuel system pressure into the fuel tank through the fuel return hose.

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Fig. Fig. 1: Relieving fuel system pressure with a vacuum pump

This latter procedure will remove the fuel pressure from the lines, but not the fuel.

The fuel system is under pressure. Release pressure slowly and contain any spillage. Use rags where needed to capture any spills Observe no smoking/no open flame precautions. Have a Class B-C (dry powder) fire extinguisher within arm's reach at all times.