Use this special disconnect tool to remove the transmission cooling lines from rear wheel drive vehicles. Works on both 3/8" and 1/2" lines. NOTE: Used with Fuel Line adapters 6923, 6539 & 6631 on Chrysler models. The 3/8" end is designed to remove the fuel line from the center port on the fuel sending unit, while the 1/2" fuel line connectors in the fuel supply line on vehicles equipped with the 6.6L Duramax diesel engine. To use GM-44581, open the appropriate size end , and slide it over the fuel sender or line. Close GM-44581 around the fuel sender or line, carefully insert it into the fitting to release the retainers, and separate the fuel lines for service.