Anyone have a good diagram of the dual tank fuel system. I have a 1989 F250 5.8 Winsor ESP. The rear fuel tank sending unit is leaking so I dropped the tank to see if I could fix it. It is rusted a bit, not bad, but the thing doesn't look like it has been used in ages! So I want to take it apart and flush it out really good, but don't want to go through that without a good diagram to make certain I get it back together properly. I will take pictures and draw my own, just want to double check. Not to mention might not be set up correctly currently from whoever doing whatever. Thanks in advance!

 

If you can drop the tank that's the hardest part. Removing the pump module is simple , just watch closely and carefully what you remove and reinstall it the same way. If you can afford it, suggest getting the module from Ford. You will need a new module to tank "O" ring and possibly the module retaining locking ring . they get pretty rusted and it is easier in the long run to install a new one. Let us know how you make out with this.

 

Yea, I have the know how to do all this. I have had fuel tanks out before, but I want to make sure I put it back together to OEM specs. Make sense? Just so I know its right...

 

Some modules have an indexing slot some don't. Just carefully install the module with the piping going in the right direction to connect the fuel lines/hoses and make sure the float will not contact anything in it's normal path of operation.

 

One other thing Hanky didn't mention; it's ever so much easier to pull the bed for access to the rear tank then to play "yank the tank". It saves having to remove the filler necks, which on something this old will most likely be very hard and brittle.

 

Yank the bed off as others have suggested. I just did this last week on my F250. It was 6 bolts and off she comes. Another thing check the fuel line between the sending unit and the fuel pump. Mine were falling apart and I would bet you will find the same issue with yours. While you got it apart I assume your going to go through both tanks. I sure would. I ended up replacing both sending units and pumps they were all in really bad shape. I had been experiencing some rough idle and after the lower pumps were replaced all that mess cleared up.

 

I am planning on doing both tanks yes, and yea, I have already gotten some of the fuel lines to put in. Others still to come. The rear sending unit is junk, but the tank is still solid. Gonna sand blast it, coat / paint it and reinstall. The filler neck wasn't too bad, looked like it has been replaced before so should be okay. I will inspect everything before putting it back together though. Thanks all.