Selector Valve

A driver-operated selector switch controls selector valve for switching fuel supply from one tank to other. Two types of valves are used. These are electrical type (type 3) or mechanical type (type 4).

The electric type, when energized by selector switch, shuts off fuel supply and return lines from one tank and opens lines to other tank. Simultaneously, in-tank pump and fuel level sender are turned off for one tank and energized for other.

The mechanical selector valve is contained within 6-port reservoir assembly and is found on type 4 high pressure fuel pump system only. This valve switches fuel supply and return lines from one tank to other in response to fuel pressure from in-tank pumps acting on its actuating diaphragm.

The diaphragm switches tank connection when under 2 psi of fuel pressure are acting on upper side of front tank and lower side for rear tank. Valve functioning depends upon proper operation of in-tank low pressure pumps. In all dual tank vehicles, excess fuel not used by engine is returned to same tank from which it was pumped.