Tire system and method of maintaining air in a tire

A tire system and a method of maintaining air in a pneumatic tire is disclosed. The system comprises a tire having a tire carcass comprising a tire cavity defined by a tire inner liner, and first and second sidewalls extending respectively from first and second tire bead regions to a tire tread region; compression actuator means (19) mounted to the tire carcass configured for operative actuation by tire deformation during a tire revolution; and a pump assembly (20) affixed to the tire carcass and comprising a compressor body (62) affixed to the compression actuator means and having an internal air chamber (64). The internal air chamber has an inlet opening (66) for admitting air into the internal air chamber and an outlet opening (70) for conducting air from the internal air chamber to the tire cavity. The compressor body (62) further comprises a piston valve member (74) operationally moving within the internal air chamber responsive to actuation by or contacting engagement with the compression actuator means (19) to compress air within the internal air chamber (64).