A clamping unit includes a drawbar having an interior surface defining a fluid transport channel. A fluid transport pipe is at least partially disposed within the interior of the drawbar and is in fluid communication with a fluid transport adapter and a fluid transport channel to enable high pressure fluid to be provided directly to a toolholder. The clamping unit further comprises at least one spring-like member positioned around the outer surface of the drawbar to provide a biasing force against an end plate. The drawbar is movable along a longitudinal axis between a locked position and a tool release position by applying and not applying hydraulic pressure against the end plate, thereby providing a quick-change feature of the invention.