A leaking oil dipstick adapter is repaired by removing a flanged nut from a threaded extension of the dipstick adapter. A gasket and preferably also gasket seal forming material are applied surrounding the threaded extension of the dipstick adapter and adjacent to an exterior side of the wall of the oil pan. A washer is applied adjacent to this gasket. A nut is threaded onto the threaded extension of the dipstick adapter and applies a compression force on the washer, compressing the gasket against the exterior surface of the wall of the oil pan. A tool is preferably used to retain the dipstick adapter and keep it from falling into an interior of the oil pan during the repair.