Abstract: An automatic fuel dispensing system including an automatic dispensing nozzle similar to dispensing nozzles which open manually to dispense liquids and shut-off automatically when tanks such as locomotive fuel tanks near the point of being filled, or for closing an automatic shut-off valve when the dispensing valve is a substantial distance from the tank being filled. The automatic dispensing system is provided with an atmospheric pressure balanced diaphragm and an internal vacuum conduit where the diaphragm operates the shut-off valve when reduced air pressure from the vacuum conduit interrupts the pressure balance of the diaphragm. The tank to be filled is provided with an air conduit connected to the internal vacuum conduit of the automatic dispensing nozzle to operate the cut-off of the nozzle to a point adjacent the outer opening of the tank fill pipe when fuel enters the air conduit.