An exchangeable filter insert that separates an unfiltered side and a filtered side of a filter, the filter having a filter housing, an inlet for liquid to be filtered and an outlet for filtered liquid. A filter bypass valve has a valve seat and a valve body guided so as to be movable relative to the valve seat and preloaded in the closing direction. The valve seat is fixed to the filter. The valve body is guided in the filter so as to be fixed to the filter. A spring that preloads the valve body in the closing direction is guided in the filter so as to be fixed to the filter. The filter insert has a spring prestresser support that, in the state in which the insert is placed into the filter housing, supports and pre-stresses the spring at its end facing away from the valve body.