An air chuck that accommodates a Schrader valve, or U.S.-type valve, in a retracted position and further accommodates a Presta valve, or French-type valve, in an extended position. The air chuck has a chuck body that slides relative to a chuck housing. A lock pin extends radially outwardly from the sliding chuck body and travels along an elongated channel in the chuck housing. When the sliding chuck body reaches its extended position, to accommodate a Presta valve, the lock pin exits the elongated channel and is received in an annular channel defined by an inside wall of an end of a cap secured to the chuck housing, and a rim of the chuck housing. A second annular channel communicates with the elongated channel to receive the lock pin when the sliding chuck body is in the retracted position. The annular channels allow the sliding chuck body to be rotated relative to the chuck housing to lock the chuck body in the extended or retracted position.