Abstract: A vehicle fuel tank has a flexible bladder disposed within a metal shell. A vent line extending from within the bladder is controlled by an altitude sensitive valve, and a pressure balance line interconnects the vent line and the space between the shell and the bladder to minimize any pressure differential across the bladder. The bladder contains a fuel level sensor having a float which moves an arm through a vertical path. A fender is suspended within the bladder and is contoured to follow the path of the sensor arm to preclude interference between the bladder and the arm.