An apparatus for providing hemostasis within a puncture through tissue includes an elongate member having a lumen extending between proximal and distal ends thereof, an expandable member carried on the distal end and a housing on the proximal end, the housing including an interior communicating with the lumen, and further including a valve assembly with a one-way valve allowing access into the housing interior upon application of a pressure differential across the valve, and a movable plunger for overriding and opening the valve.