Fuel sender for motor vehicle fuel system

Abstract

Fuel sender at a remote or terminal end of a suction circuit of a fuel system of a motor vehicle. The fuel sender includes an unsealed reservoir in a fuel tank of the vehicle replenished by return fuel from a return fuel circuit of the fuel system and a junction chamber in the reservoir communicating with the terminal end of the suction circuit and with each of a primary flow channel and a secondary flow channel. The primary flow channel terminates at a primary screen in the fuel tank outside the reservoir. The secondary flow channel terminates at a secondary screen inside the reservoir. The secondary flow channel is restricted relative to the primary flow channel so that vacuum in the suction circuit induces flow in the primary flow channel in preference to flow in the secondary channel. Under low fuel conditions, the primary flow channel is blocked and vacuum in the suction circuit induces flow in the secondary flow channel from the reservoir. The secondary screen is flexible and actuates a differential pressure responsive bypass valve to connect the secondary flow channel directly to the reservoir when both the primary and the secondary screens are blocked.