On my '95 F250 460ci the rear fuel tank seems to Fill the front tank...it only happens when i am driving, if i leave it sit the levels stay the same. I wasnt sure at first but i ran the front tank dry (not good for the fuel pump i know) and i filled the rear full. As i drove it empty i switched back and the front was 1/4 full. So my question is, is this normal? and if so is it something with the 460 or model? My previous truck a 93 with a 351W Never did this... Any ideas?
Thanks in advance.

 

This issues was just discussed, a search should turn up some answers for you.
Craig

 

The issue you describe is referred to as "cross-flow"/ A very common issue and it was a problem that triggered a recall by Ford. The problem is caused by the the shuttle valve inside the fuel delivery module (FCM) not properly closing in the tank that is filling up. In your case the front FDM is bad.

Some have been lucky replacing only the fuel pump, others have required replacing the entire fuel delivery module.