BREAKAWAY CLOSURE FOR CAPLESS TANK FILLER NECK

A filler neck closure unit includes a frangible portion that is configured to break along a fracture line when an outer portion of the closure unit is hit by a strong blow. The closure unit includes an inner portion that remains coupled to a filler neck to block discharge of liquid fuel and fuel vapor from the filler neck and an outer portion that takes the blow and separates from the inner portion at the fracture line.