Product description

Any fuel tank must be vented; it is a closed system, so to speak. If this were not the case, a negative pressure (vacuum) would be created, affecting the fuel supply and possibly even leading to the implosion of the fuel tank. For the above reasons, each fuel tank is equipped with a vent, so that the space released is immediately filled with air (so that no underpressure can occur). Typically, this vent is located in the fuel tank cap and is constructed so that air can be drawn in, but no fuel can escape.

To ensure proper ventilation of the fuel tank, the tank is equipped with vents at locations where air bubbles may form, which remove negative or positive pressure via the filler neck or an expansion tank. The excess pressure is created by the expansion of the fuel. Depending on the construction of the fuel tank, this overpressure can only be eliminated by means of venting pipes or an expansion tank must be used. In the Volkswagen Vanagon, two expansion tanks are used to collect the excess pressure, which are connected to the fuel tank by pipes.

The vent hose mentioned here is a preformed plastic hose of which there are two present. They are connected by a flexible hose to the lower part of the expansion tank and, on the other hand, also by a flexible hose to the pressure expansion line.

It is also recommended to replace the hose at the same time, which is indicated in the options tab.