A piston-in-sleeve accumulator includes a cleaning element positioned on the piston and configured to remove and prevent debris from lodging between the piston and a cylindrical nonpermeable sleeve within which the piston slides. A seal on the piston is positioned to engage an opposing surface in the event of a leak, and thereby prevent the possibility of a complete drainage of pressurized fluid from occurring through the accumulator's fluid port. A position contactor switch is further provided to signal position of the piston within the accumulator.