A fuel filter element, which may be selectively arranged in a filter housing and may separate in the filter housing an untreated space communicating with an inlet and a return line of the housing from a treated space communicating with an outlet of the housing, may include at least one end disk, and at least one closure element, which in an operationally ready state of the fuel filter may close off the return line. The closure element may protrude eccentrically axially away from the at least one end disk. The closure element may have a seal on a surrounding surface and that, in the operationally ready state, may be in contact with a surface of the return line. In the operationally ready state, a portion of the closure element may be located in a filter chamber of the filter housing and another portion of the closure element may be located in the return line.

A fuel filter element, which may be selectively arranged in a filter housing and may separate in the filter housing an untreated space communicating with an inlet and a return line of the housing from a treated space communicating with an outlet of the housing, may include at least one end disk, and at least one closure element, which in an operationally ready state of the fuel filter may close off the return line. The closure element may protrude eccentrically axially away from the at least one end disk. The closure element may have a seal on a surrounding surface and that, in the operationally ready state, may be in contact with a surface of the return line. In the operationally ready state, a portion of the closure element may be located in a filter chamber of the filter housing and another portion of the closure element may be located in the return line.

A fuel filter for a fuel supply system of an internal combustion engine may include a filter housing, which may have an untreated-side inlet, a treated-side outlet, and an untreated-side return line. The fuel filter may also include a filter element arranged in the filter housing, and a closure element, which in an operationally ready state of the fuel filter may close off the return line. The fuel filter may include an untreated space and a treated space, and may separate in the filter housing the untreated space communicating with an inlet and the return line from the treated space communicating with the outlet. The fuel filter may further include a pressure sensor configured to measure a pressure build-up in the treated space, wherein the fuel filter may be configured to enable the pressure build-up to reach a predetermined threshold at which the engine may be started.

A fuel filter for a fuel supply system of an internal combustion engine may include a filter housing, which may have an untreated-side inlet, a treated-side outlet, and an untreated-side return line. The fuel filter may also include a filter element arranged in the filter housing, and a closure element, which in an operationally ready state of the fuel filter may close off the return line. The fuel filter may include an untreated space and a treated space, and may separate in the filter housing the untreated space communicating with an inlet and the return line from the treated space communicating with the outlet. The fuel filter may further include a pressure sensor configured to measure a pressure build-up in the treated space, wherein the fuel filter may be configured to enable the pressure build-up to reach a predetermined threshold at which the engine may be started.