F 250 4WD HD Pickup V8-460 7.5L VIN G EFI (1997)
Fuel Filler Cap: Description and Operation
The fuel tank filler cap is sealed and includes a built-in pressure-vacuum relief valve. Fuel system vacuum relief is provided after 3.5 kPa (0.50 psi) and
pressure relief after 11.0 kPa (1.6 psi). Under normal operating conditions, the fuel tank filler cap operates as a check valve, allowing air to enter the
tank as fuel is used, while preventing vapors from escaping the tank through the cap.
