Abstract: A piston assembly for a tensioner which has a hollow piston body having a first end and a second end; and a cap. At least a portion of the cap fits into the first end of the piston body. The cap has a head and may also have a stem connected to an underside of the head. The cap may also have at least one slit for venting fluid, having 5 a width and a depth. The slit may extend from an outer circumference of the stem and across the underside of the head. The slits may be parallel to a centerline of the cap or angled relative to the centerline of the cap. A plurality of slits may be present on the cap. At least two of the plurality of slits may have different widths or different depths. The slits may be evenly 10 spaced around the cap.