GM Bonneville/Eighty Eight/LeSabre 1986-1999

Relieving Fuel System Pressure



See Figure 1

To prevent damaging the electrical systems, make sure the ignition key is in the OFF position when disconnecting or reconnecting the negative battery cable.

  1. Disconnect the negative battery cable to avoid possible fuel discharge if an accidental attempt is made to start the engine.
  3. Loosen the fuel filler cap to relieve fuel tank vapor pressure.
  5. If necessary for access, remove the fuel injector sight shield, then remove the fuel pressure connection cap.
  7. Wrap a shop towel around the fuel pressure connection fittings while connecting the gauge to prevent fuel spillage.
  9. Connect fuel pressure valve J 34730-1A or equivalent to the fuel pressure relief connection at the fuel rail.

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Fig. Fig. 1: Although a special tool is available, you can use a screwdriver to depress the fuel pressure connection, to relieve fuel pressure

  1. Install a bleed hose into an approved container and open the valve to bleed the system pressure. The fuel system is now safe for servicing. Drain any fuel left in pressure gauge into the approved container.
  3. Install the fuel filler cap.