Does a fuel pump equal a water pump?

Consequences of incorrect allocation/use

Information on diagnostics

Incorrectly allocating the fuel pump (petrol pump, diesel pump) can cause major problems in the engine of vehicles. Sometimes the pumps are also used to pump liquids other than fuel. This article describes which problems could arise as a result.

Wrong pump

Time and again, an incorrect fuel pump for the intended purpose or electronic equipment is selected from catalogues during replacement or for retrofitting.

This then delivers too high or too low pressure.

Improper use

A more serious case is when a fuel pump is used in a manner for which it is not intended.

Fuel pumps are designed to convey fuel (petrol, diesel).

For most people, this goes without saying. Nevertheless, complaints are occasionally received concerning fuel pumps that have been used to convey other fluids (water, oil, battery acid).

Fig. 2, for example, shows a type E3T in-line pump, which is intended for installation outside the fuel tank in the fuel line, situated in the tank. The rubber sleeve, which enveloped the fuel pump, has been dissolved by fuel and is blocking the fuel pump and the rest of the fuel system.

Crystalline deposits caused by unsuitable fluids In some cases, the cause of deposits such as these can only be determined through timeconsuming chemical tests. | Pierburg | Motorservice — Fig. 1: Crystalline deposits caused by unsuitable fluids In some cases, the cause of deposits such as these can only be determined through timeconsuming chemical tests.

Competitor’s pump (left) and E3T with rubber jacket from Pierburg | Pierburg | Motorservice — Fig. 3: Competitor’s pump (left) and E3T with rubber jacket from Pierburg

Rubber sleeve

This rubber sleeve compensates for the larger sizes of competitors’ pumps, in order that fuel pumps sold by Motorservice can fit in existing mountings (see Fig. 3).
In addition, the rubber sleeve has the advantage of preventing vibrations from being transmitted to the body.