Audi 80/Avant (B4)

Since 1991-1995 of release

Repair and car operation



Audi 80/Avant
+ The description
+ Engines
+ System of release of the fulfilled gases
+ Cooling system
- Fuel tank and the fuel pump
   Fuel tank
   The gauge of level of fuel
   The fuel accumulator
   Топливопровод
   The fuel pump
   Replacement of the fuel filter
+ The air filter and воздухозаборные channels
+ Injection system
+ Coupling
+ Transmission and transmission
+ Suspension bracket and steering
+ Brake system
+ Antiblocking system of brakes
+ Wheels and tyres
+ Kuzovnaja electrosystem
+ Ignition system
+ Illumination
+ Signalling devices
+ Devices and auxiliary devices
+ Heating and ventilation
+ Body elements
+ Search of malfunctions
+ Specifications



Fuel tank

The fuel tank of car Audi 80 is technically enough perfect, but also it has been improved for all-wheel drive models. The difficult form of a fuel tank helps to achieve high-capacity a tank without damage to volume of a luggage compartment. In the middle of a fuel tank you see the fuel pump and the gauge of the indicator of quantity of fuel. On the right at the top of a bulk branch pipe with all ventilating and bulk hoses.


Back right wheel niche with removed подкрылком

1 – a bulk branch pipe;
2 – the valve самотека;

3 — a fuel tank;
4 — a broad tank.

The fuel tank in front-wheel models Audi 80 has capacity about 66 l, in all-wheel drive versions it contains a minimum of 64 l. To reach a flat surface of the bottom of a luggage compartment with possibility of loading of salon, a fuel tank establish in a car forage under the sheet bottom of a luggage compartment. The tank is made of plastic – a material supposing almost unlimited possibilities at giving of the form. These possibilities have been used for all hundred percent. For example, the fuel tank of all-wheel drive models occupies almost all free spaces under the body bottom that becomes to achieve probably большего volume. Therefore the form of this detail of the car looks enough strange. That during a trip the parts of a fuel tank located more low were emptied also, skilful reception has been applied: in this bottom area there is a pump, at the working engine constantly pumping over fuel in located above a part of a fuel tank. And it occurs simply enough: returnable fuel from drain топливопровода picks up additional fuel in the pump case and transfers it upward.

One more reception has been applied to cope with chambers of various volume in a fuel tank: the hose conducting directly in area всасывания so it is filled first of all is connected to a bulk branch pipe. It is important, for example, in a case when the small amount of fuel from the spare canister is added.

 The help: before to start to work with system of giving of fuel, you necessarily should disconnect earthing cable from the storage battery. Inadvertent electric short circuits can serve as the reason dangerous искрообразований.

For what ventilation of a fuel tank is necessary?

  • Ventilation of a fuel tank is important for uninterrupted giving of fuel: in the same quantity in which fuel is spent, in a tank air should arrive, otherwise in a fuel tank the lowered pressure is formed, and fuel receipt will stop.
  • It is necessary to ventilate a fuel tank to give the chance to contents to expansion at heating.
  • At refuelling it is necessary, that air could leave a tank because differently poured fuel again will rise to a bulk branch pipe and will start to pour out.

Ventilation of a fuel tank in car Audi 80

  • Directly behind a bulk branch pipe the ventilating pipeline of a fuel tank is connected. The ventilating channel conducts at first in the so-called valve самотека. Last closes the pipeline as soon as the car bends aside more than on 45 . Thus fuel leak through ventilating channels is prevented at failures. After passage of the air valve the ventilating pipeline conducts, however, not at once outside, and comes to an end in a tank with the activated coal in the right forward wheel niche. Its appointment – to catch fuel steams passing through this pipeline (arisen, for example, as a result of a warming up of a contained fuel tank). At the working engine these gases at certain loading of the engine again are exhausted from a tank with the activated coal. When it should occur, defines the electromagnetic valve operated depending on loading.
  • In parallel to this system the air valve opens at refuelling a broad tank of the fuel tank located in the bulk channel (in the right back wheel niche) in the form of separate capacity. Thus, at increasing level of fuel fuel steams instead of it to disappear in atmosphere there can be superseded.
  • During movement on this way external air depending on the spent quantity of fuel so in a tank it is not formed depression arrives.