Abstract: An apparatus for clamping tire tubes for repair thereof. The apparatus includes a base with a frame extending upwardly therefrom. A mandrel is attached to the upper end of the frame. A vertically movable actuating rod is positioned adjacent the frame and biased downwardly by a spring, the force of which may be adjusted. The lower end of the actuating rod is connected to a foot pedal for overcoming the force of the spring and raising the rod. The upper end of the rod has a yoke assembly connected thereto. The yoke assembly has a substantially U-shaped yoke forming a pair of upwardly extending arms, each arm having a substantially horizontal clamping bar connected thereto. The yoke is preferably at least partially flexible so that the arms will deflect outwardly as a result of the downward force exerted by the spring when the clamping bars engage a tire tube positioned on the mandrel.