Fuel Level Vent Valve

WARNING: This page is about a different car, the 2015 Jaguar XF, 2014 Jaguar XF, and 2013 Jaguar XF. However, it is still accessible from the selected car via links, so may be relevant.

The fuel level vent valve is located in the upper half of the tank and is connected into a separator which is connected to the tank breather. The main purpose of the fuel level vent valve is to control the fill volume of the tank.

During filling, air trapped inside the tank and a small amount of vapor is passed via the fuel level vent valve to the tank breather. The air and vapor mix then vents to atmosphere through the breather. During filling, when the tank reaches its full level, the fuel level vent valve closes and prevents air/vapor passing through to the tank breather. The resulting back pressure causes refueling to stop automatically.

The fuel level vent valve is always open when the fuel tank is below full, providing an unrestricted air/vapor outlet to the tank breather.