Abstract: A lowering mechanism for a hand held jacking tool comprises a caulking gun jacking mechanism. The lowering mechanism comprises a lowering plate on top of the holding plate, a pushing lever connected with a hinge attachment to the lowering plate at a rear end, wherein the pushing lever is pivoting around a pivot structure connected to the lever or holding plate a distance backward from the hinge attachment, causing the lowering plate to grip the jacking shaft when the lever is pushed downwards and then, in turn, pushing the holding plate downwards and loosening it from the jacking shaft and moving it down along the jacking shaft a distance determined by the pivoting action of the lever. The lowering plate is held in place by a spring biasing the lowering plate towards the holding plate.