Fuel Filter: Description and Operation

GF47.20-P-2101PE Fuel Filter With Integrated Fuel Pressure Regulator, Component Description
- ENGINE 271.921 in MODEL 203 up to Model Year 8
- ENGINE 271.940 in MODEL 203 up to Model Year 8
- ENGINE 271.946 in MODEL 203 up to Model Year 8
- ENGINE 271.948 in MODEL 203 up to Model Year 8
- ENGINE 271.955 in MODEL 209
- ENGINE 271.940 in MODEL 209





Location
55/1 Fuel filter with integrated fuel pressure regulator
75 Fuel tank

The fuel filter with integrated fuel pressure regulator is mounted behind the left fuel tank chamber.

Task
The fuel filter filters out the impurities from the fuel and prevents contamination in the fuel injection system.
The fuel pressure regulator regulates the fuel system pressure for fuel injection.





Design
55/1 Fuel filter with integrated fuel pressure regulator
CAN Pressurization line
PUMP Feed line from fuel pump
Fuel tank Return line to the fuel tank
Mot Fuel pressure line to the engine





Function
55/1 Fuel filter with integrated fuel pressure regulator
55/3 Valve
55/5 Diaphragm
55/6 Compression spring
55/9 Filter element
55/10 Throttle
55/40 Fuel pressure regulator (diaphragm pressure regulator)
b Aeration/Ventilation of the fuel pressure regulator
A Fuel feed from fuel pump
B Fuel return flow to fuel tank
C Fuel (at regulated fuel pressure) to engine

The fuel pressure regulator (55/40) regulates the fuel system pressure to approx. 3.8 bar via the fuel return quantity to the fuel tank.

If the set fuel pressure is exceeded, the diaphragm (55/5) is pushed against the push spring (55/6) and the valve (55/3) attached to the diaphragm opens the passage for the fuel return to the fuel tank (B). If the set fuel pressure falls below the limit, the valve is closed again by means of the push spring.

The filter insert (55/9) of the fuel filter is integrated in the panel housing and fuel flows through the filter insert from outside to inside. As a result any impurities are trapped.