OTC 7937 Transmission Oil Cooler Line Disconnect Tool for GM Specially designed to work in tight places So simple to operate you can do it with just one hand After insertion into the quick-connect fitting on 1/2 inch diameter lines a quarter turn of the tool quickly and easily releases the fitting on the transmission end of the transmission-to-radiator oil cooler line Works on 2WD and 4WD pickups and vans with electronic shift overdrive automatic transmissions