Ford Windstar Owner's Manual page 310

Filling Your Fuel Tank With Fuel
Open the fuel door (located on the driver's side of the
1.
vehicle).
Unscrew the fuel cap by exerting pressure on the plastic cap
2.
and rotating the fuel cap counterclockwise.
Turn the fuel cap 3/4 of a turn until a hissing sound is
3.
heard. Wait until the hissing sound stops and then continue
rotating counterclockwise to remove the fuel cap.
Follow the fuel cap removal instructions and use caution to
4.
minimize the possibility of fuel spraying when you unscrew
the cap.
The fuel system may be under pressure. If the fuel cap is
venting vapor or if you hear a hissing sound, wait until
it stops before completely removing the cap.
Turn the fuel cap 3/4 of a turn to relieve any pressure
and vacuum in the fuel tank. The cap will start
unthreading after 3/4 of a turn.
310
WARNING
WARNING