Dual Function Reservoir (Gasoline Engine)

The fuel tank selector valve on gasoline-engine vehicles is located in fuel filter/reservoir, mounted on left frame rail. The valve is not actuated electrically. The valve is operated by fuel pressure from the low-pressure in-tank fuel pumps.

When tank selector switch is in "FRONT" or "REAR" position, power from fuel pump relay is directed to front or rear tank fuel pump, respectively. Pressurized fuel from fuel pump moves a diaphragm in dual function reservoir, connected to sliding supply and return shutoff valves. The shutoff valves allow fuel to be drawn and returned to proper tank. See Figure and Figure .