Originally Posted by Paintinfool3
well I still have to believe it is a venting problem on the front tank now but once I try that I am out of ideas ... they should equalize they both fill fine now so in theory they should both empty fine too ... the two tank drains both work to empty the tanks
That is perplexing! If they fill fine why not pump fine. It has to be an air problem like you believe. I have not personally dealt with it yet but I actually find this fascinating.
I wonder if since the tubes you end up pumping from are only 1/2" if just the slightest vent pressure imbalance just causes one side to move more water then the other. Ill bet that if there was a secondary low point water tube connecting the two that was say 1" diameter it would solve the equalization problem.
I am seriously thinking about a mod that disconnects the two tanks, adds a second filler flange and makes them independent of each other. Then have a 3 way valve I can turn when one tank is exhausted. Had 74 F250 with that kind of setup for dual gas tanks. Had an electric switch on the dash to switch the gauge from tank to tank. The valve was behind the seat on the floor.