Abstract: An improved pneumatic tool for the removal and application of tire cross chains configured having a manually actuated valve connected at its inlet port to a compressed air source and at its outlet port to a pneumatic diaphragm motor for actuation of a diaphragm. The control valve includes an air bleed port which allows air to escape through the valve when the trigger or other operating mechanism is released deactivating the valve. This feature allows an almost immediate recovery of the jaws to the open position. The pneumatic tool for the removal and application of tire cross chains also includes a fixed jaw support assembly having a base plate for attachment to the face of the pneumatic diaphragm motor, the fixed jaw support assembly having a pair of upright members attached to the base plate and extending perpendicularly and in spaced apart relationship to one another to accommodate the attachment of the fixed and the moveable jaws between the two upright members thereto.