Sealing surfaces must be clean and free from foreign matter to maximise the metal-to-metal and elastomeric seal effectiveness. The tool mates into the 5.5” hub using a specifically shaped interface made from soft materials ensuring alignment without damage to the hub. A hydraulic motor drives the cleaning head with Scotch Brite scouring pads fitted to its mounting faces. Importantly, there is no direct metal contact with the hub. The scouring pads are available in three difference grades (course, medium and fine).