I have a 1988 F-250 2wd V8 with dual fuel tanks which are equipped with a switch in the cab to go from front to rear or vice versa. My problem is that when the rear tank is filling the front tank when I am using the rear tank. Example: front tank has 1/4 tank when using the rear tank after about 40 miles the front tank is just about full. Anyone have any ideas. I don't use the front tank due to I have to replece the filter.

Thank You
Mark

 

There Was A Recall On This I Just Took Mine To The Dealership And They Fixed It At No Charge

 

You have a bad selector valve (stuck "O" ring) or you rear fuel pump is inoperative.

 

SubFord .... I think it would be the front tanks pump with the problems since that is the one crossfilling. I know the 88 is a different system than my 90, but don't they both use the same filter?

 

No they are completely different systems. You would be right if it was a 1990. The 1990 have check valves in the FDM where the same check valve in the 1987 - 1989 are in the Hi-Pressure pump on the frame. You do not have the selector valve on the frame where his does and it is what redirects the fuel from and to each tank.