Boot o-ring. Right.1.8 LITER. A circular disk covered in rubber or plastic with a hole in the center where the edge is sometimes tensioned by a spRing that prevents fluid from leaking at the Rack & Pinion Housing Dust Boot. A component which prevents leaks at the Rack & Pinion SteeRing Pinion Shaft. Included in gear assembly. Rack and Pinion O-Ring. Rack and Pinion Seal. and. and O -. And Stee Shaft O -. Boot o -. Inner tie rod o -. Included with: Gear assembly, Gear assy, SteeRing gear.