Abstract: This tool is used to reface the filler necks of the radiators of coolant systems of Caterpillar equipment. Primarily, it includes a circular plate, having a number of radial cutting blades secured to it. It also includes a sleeve, for being received on the stud within the filler neck, and it further includes bolts for receiving a wrench to rotate the tool, and a depth control bolt is included, for adjusting the depth of cut of the blades of the device.