Gas tanks overflow

[hookedfeather]

My '95 E-350 v8 4x4 has dual gas tanks. Fuel pumps in both tanks pump the excess gas (what the engine doesn't use when running) into the other tank rather than back into the source tank. The result is that if I run on tank No.1, tank No 2 slowly fills up and overflows, and vice versa. Fumes are terrible. Any fix for this?

[Ford_6L_E350]

Swap the return lines so they dump into the source tank?

Mike

[carringb]

What he said. If this happens with either tank selected, somebody mixed up the lines where they connect to the selector valve. If it only happens with one tank, you need a new selector valve.