Existing difficulty? The area surrounding the injection pumps on later model 4 valve ISC 8.3 liter and ISB 5.9 liter engines is very difficult to access when removing the fuel supply lines. Remove with easy! This specialty socket has been designed with a custom slim configuration and a 3/8" square drive to fit into this confined area. This unique 3/4" Fuel Injection Flare Nut Socket gives the technician the ability to access and remove fuel pump lines with little effort. Used with a ratchet and extension, the socket slides along the fuel line onto the flare nut which now can be loosened for pump removal. The Flare Nut Socket is also used to tighten the fuel line nuts when the injection pump isreattached to the fuel lines.Not for ISM engines. Package includes: 1 pc