Fuel filter insert, and fuel filter comprising a prefilter element and a main filter element and comprising a water separating unit

A fuel filter comprising:

• a filter housing;
• a fuel filter insert disposed in the filter housing and comprising
• a prefilter element and
• a main filter element arranged atop the prefilter element in an axial direction relative to a longitudinal axis of the fuel filter insert,
• wherein the main filter element comprises
• a water separating unit configured to separate water contained in a fuel to be filtered, and
• wherein the water separating unit comprises a water discharge channel for water separated from the fuel,
• wherein the water discharge channel is extending in the axial direction at least partially through the prefilter element;
• wherein the water discharge channel of the fuel filter insert is fluidically connected with a water collecting chamber of the filter housing;
• wherein the fuel filter insert further comprises:
• a flow channel for fuel that has been prefiltered by the prefilter element,
• wherein the flow channel is arranged between the prefilter element and the main filter element,
• wherein the flow channel is immediately delimited in the axial direction by an end disc of the prefilter element that is facing the main filter element and by an end disc of the main filter element that is facing the prefilter element.

A fuel filter comprising:

• a filter housing;
• a fuel filter insert disposed in the filter housing and comprising
• a prefilter element and
• a main filter element arranged atop the prefilter element in an axial direction relative to a longitudinal axis of the fuel filter insert,
• wherein the main filter element comprises
• a water separating unit configured to separate water contained in a fuel to be filtered, and
• wherein the water separating unit comprises a water discharge channel for water separated from the fuel,
• wherein the water discharge channel is extending in the axial direction at least partially through the prefilter element;
• wherein the water discharge channel of the fuel filter insert is fluidically connected with a water collecting chamber of the filter housing;
• wherein the fuel filter further comprises:
• a fuel pump,
• wherein the filter housing comprises
• a lateral fuel outlet connected to the prefilter element and
• a lateral fuel inlet connected to the main filter element,
• wherein the pump is connected between the lateral fuel outlet and the lateral fuel inlet,
• wherein the fuel filter insert further comprises
• a flow channel for fuel that has been prefiltered by the prefilter element,
• wherein the flow channel is arranged between the prefilter element and the main filter element,
• wherein the flow channel is immediately delimited in the axial direction by an end disc of the prefilter element that is facing the main filter element and by an end disc of the main filter element that is facing the prefilter element,
• wherein said end disc of the prefilter element and said end disc of the main filter element are seal-tightly contacting an inner side of the filter housing, and
• wherein the flow channel is fluidically connectable by the lateral fuel outlet with the fuel pump to pump the fuel prefiltered by the prefilter element through the fuel inlet to the main filter element.