A lash compensator for a valve train component of an internal combustion engine is provided that includes an end-cap arranged within a reverse-spring control valve assembly of an axially moveable piston. The piston has a first reservoir and an inner radial wall configured with a through-aperture. The reverse-spring control valve assembly has a control valve housing, a bias spring, an end-cap, and a closing body. The end-cap is configured with a cupped end; an inner side of the cupped end receives a second lower end of the bias spring, and an outer side of the cupped end engages an upper portion of the closing body. The end-cap minimizes or eliminates the variation in flow resistance caused by a variation in end-coil geometry of the second lower end of the bias spring.