A tool suitable for loosening, twisting, removing or replacing an oil filter or a cover of said oil filter or of a thermostat from a liquid separator wherein the filter element is adapted to be fitted with a cap or cover element at the top, wherein the cap or cover element is adapted to be provided with an elevation comprising a cut-away that can be opened with said tool,
- wherein the tool is provided with a detailing with a form that is complementary to the cut-away in the cap or cover element of the filter element, and
- wherein the tool comprises a hollow tubular part, wherein a circular edge of the tubular part is provided with at least one arch-shaped extension in the axial direction, wherein this extension is provided with at least one notch in the axial edge of the extension, wherein the notch extends in the circumferential direction of the tubular part.