An assembly for the removal of contaminants from a contact zone between respective contact surfaces 6, 8 of a first component 2 and a second component 4. At least one of the contact surfaces has a low friction element 10 provided with grooves 12 which extend through the contact zone such that, in operation, a pressure difference across the contact zone causes contaminants entering the grooves 12 to be expelled along the grooves 12 from the contact zone.