Evaporative Check Valve: Description and Operation

PURPOSE/OPERATION
The fuel check valve is used to prevent fuel leakage if the car were to roll over. This valve is connected in the fuel vapor line (between the canister and the overfill limiter) and is installed on the fuel tank. The fuel check valve contains two check balls. Under normal conditions, the gasoline vapor passage in the valve is opened, but in the event a roll-over occurs, one of the balls closes the fuel passage, thus preventing fuel leakage.