Fuel tank ventilation

The fuel leaving the tank would inevitably create a vacuum in it, if there were no system connecting the tank with external air. Through this system, air can enter or exit as the volume of fuel in the tank changes. In most cases, the fuel flows flawlessly. But when filling fuel, difficulties may arise if the car was manufactured before February 1978. The air in the fuel tank cannot escape quickly enough, the fuel begins to bubble up at the filler neck. The reason for this phenomenon is the bending of the ventilation duct in the place where it passes through the longitudinal beam of the body. In order to avoid such a difficulty, subsequently, helical springs were inserted into the pipelines, which did not allow the pipelines to bend.

Now only this ventilation duct is available as a spare part. Of course, it can also be mounted in those car models that were designed and released earlier.

A few more words about the fuel tank cap. In a diesel car, it does not have a vent. This means that the plug closes the tank absolutely hermetically at the filler pipe. If you. for example, once you forgot a cap at a gas station, you need to buy a similar one: it has an inscription on the inside "without ventilation". The vented cap also works well, but when driving on extreme, curvilinear roads, you may find that a small amount of fuel leaks out.