FORD 2013 F-550 v.1 - Manual (Page 193)

Fuel Filler Cap
WARNING: 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.
WARNING: If you do not use the proper fuel filler cap, excessive
pressure or vacuum in the fuel tank may damage the fuel system
or cause the fuel cap to disengage in a collision, which may result in
possible personal injury.
Note: 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, Motorcraft® or other certified fuel filler cap is not used.
Your fuel tank filler cap has an indexed design with a 1/4th turn on and
off feature. When fueling your vehicle:
1. Turn the engine off.
2. Carefully turn the filler cap counterclockwise until it spins off.
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 clockwise until it clicks at
least once.
If the Check Fuel Cap light or a Check Fuel Cap message appears in the
instrument cluster and stays on after you start the engine, the fuel filler
cap may not be properly installed.
If the fuel cap light remains on, at the next opportunity, safely pull off of
the road, remove the fuel filler cap, align the cap properly and reinstall
it. The check fuel cap light or Check fuel cap message may not reset
immediately; it may take several driving cycles for the indicators to turn
off. A driving cycle consists of an engine start-up (after four or more
hours with the engine off) followed by normal city and highway driving.
192 Fuel and Refueling
2013 F-250/350/450/550 (f23)
Owners Guide gf, 1st Printing
USA (fus)