379 uneven draw or return

Before I bought my truck I was running a 2000 379 for an o/o that did the same thing. Pete's have a valve on the bottom and a valve on the top of each tank. If memory serves correctly the valve on the top of the tank that was going mt was bad, and forcing the return to flow into the opposite side only. It got to the point that I filled both tanks and was headed home, it actually ran out of fuel because the pass side went mt and took it's prime, I was sitting on the side of the road with a slam full tank of fuel in the drivers side, actually overflowed, and engine had no fuel!

 

most of the ones I have experience with have a splitter on the cross member at the transmission, just follow the lines....generally when they are not working the vent line is stopped up or a piece of trash is in the tank on the pickup side on the full tank

 

make sure to check the vents, there is a ball valve in there that gets plugged up with dust

 

I need to check that, mine fills the right side tank when driving and evens out when you shut it off for a couple of hours. I closed the return line valve on the right tank about half way and its working ok now but I know it isn't right.

 

The splitter valve on the return is also some kind of check valve with springs and such in there, mine was doing the same thing, I took that splitter apart and there was some pieces of rubber in there from replacing fuel lines on the return line ahead of that valve.