Ford F-150 Owner's Manual page 294

Maintenance and Specifications
Fuel Filler Cap
Your fuel tank filler cap has an indexed design with a 1/4 turn on/off
feature.
When fueling your vehicle:
1. Turn the engine off.
2. Carefully turn the filler cap counterclockwise 1/4 of a turn until it
stops.
3. Pull to remove the cap from the fuel filler pipe.
4. To install the cap, align the tabs on the cap with the notches on the
filler pipe.
5. Turn the filler cap clockwise 1/4 of a turn until it clicks at least once.
If the digital display, if equipped,
reads "CHECK FUEL CAP" and
stays on after you start the engine,
the fuel filler cap may not be
properly installed. Turn off the
engine, remove the fuel filler cap, align the cap properly and reinstall it.
If you must replace the fuel filler cap, replace it with a fuel filler
cap that is designed for your vehicle. The customer warranty may
be void for any damage to the fuel tank or fuel system if the
correct genuine Ford or Motorcraft fuel filler cap is not used.
The fuel system may be under pressure. If the fuel filler cap is
venting vapor or if you hear a hissing sound, wait until it stops
before completely removing the fuel filler cap. Otherwise, fuel may
spray out and injure you or others.
294
2006 F-150 (f12)
Owners Guide (post-2002-fmt)
USA (fus)