I thought I was getting real poor gas milage because my rear tank ran empty in such little distance, now I realize that for some odd reason, my gas is emptying from my rear tank into the front tank (shipment tank).

The main problem is that my front tank has a bad seam that leaks and I ran it empty so I could fix or replace it.
Well needless to say when the truck is facing downward, the tank that I emptied started leaking. I know the guage is right because I literally ran it out of gas to lessin the siphoning. Now it has a 1/4 tank again.

Why is this happening? Now I have to find away to drain all that gas back out inorder to do a fix of the tank?

Actually, Is it possible to do away with the shipment tank altogether. I never really use it at all... I have no earthly idea how to do it because im sure it ties in to the rear tank some how but that would save me the headache of having to replace it?

 

Need to post some info about your truck so we can help.

 

My truck is a 1991 F150 4.9 Inline 6cyl. 2 wheel drive. Long wheel base.

Has only 101,000 original miles; Mainly highway. Has had everything maintained or replaced on schedual by the book from day one.

 

Problem is that the rear tank is pumping into the front tank due to faulty "drainback" valves(can't think of the exact terminology right now). There was an old recall that confronted this and put valves onto each of the fuel pumps. Only way to fix it is to replace the fuel pumps, or find a dealer that has the old recall parts. It would take a little research, but I could come up with part numbers if needed.

 

What about dropping the front tank completely, Is this possible to do and will I have to find away to put a jumper wire into the fuel pump harness inorder to fool the computer that the tank is still there?

 

You can get a new tank for about $100. Doing away with it is a lot more trouble than replacing it. But, you could install a check valve(just remembered) onto the front fuel pump, and just run on the rear tank. I could try to find a part number.

 

I didnt know you can just replace the check valve, I figured I would have to replace the whole fuel pump assembly.

 

The "check valve" was the recall part.