Fill Control Vent System
OPERATIONFill control and fuel vapor venting is accomplished by the following method:
- A vent line attached to the fuel tank filler pipe, extends inside the, fuel tank.
- The evaporative, emission, valve mounted in the top panel of the fuel tank and the evaporative emissions tube attached to the evaporative emissions canister also contribute, to fill control by controlling pressure in the fuel tank.
- As the fuel level rises to cover the fill vent, pressure rising in the fuel tank causes fuel to back up and shut off the fuel dispensing nozzle.
- The vent system is designed to provide an air space, approximately 10 percent of the fuel tank volume, above the fuel level in a full fuel tank.
- The air space allows for thermal expansion of fuel and provides clearance between the fuel level and the evaporative emission valve, which is mounted in the top panel of the fuel tank.
- The clearance is sufficient to allow fuel vapor venting through the evaporative emission valve under all static and most dynamic vehicle conditions.