Abstract: A pneumatically powered pin retractor is disclosed. Semi-trailers comprise tandems which can be slid forward and backward when a set of pins are retracted. In conventional semi-trailers, manually pulling a pin release lever located on the side of the tandem rotates the pin control shaft, thereby retracting the pins. The disclosed pin retractor comprises a lever arm attached to the pin control shaft, a pneumatic ram to push the lever arm thereby rotating the pin control shaft and retracting the pins, and a means for activating the pneumatic ram. The source of air pressure to power the pneumatic ram is normally the service air tank on the tandem.