Piston Assby with Pin, Retainer & Rings $72.85

Includes piston, rings, piston pin & snap rings.

The piston rings provide compression in an air compressor pump by providing the seal in between the cylinder wall and the piston. In an oil-bath pump, there are usually two compression rings and one oil (scraper) ring to keep oil from passing the piston and into the head. In an oil-free pump, the piston is Teflon-coated and doesn’t require lubrication. If your pump is pulling oil into the head or if compression is very low (oil-bath pumps), replace the rings. If your pump isn’t pressurizing or if the piston ring is damaged along the outer perimeter (oil-free pumps), replace it. Also replace the cylinder sleeve when replacing the compression ring (oil-free pumps).