I've recently bought a 02 F250 7.3. Awesome truck, but I have a problem with the fuel tank overflowing. If I fill it full (untill fuel pump shuts off automatically) it leaks diesel fuel all over the tank and eventually all over where I park it. Not a huge deal, but would like to correct it if possible.

I tried to look at the top of it for how the breather etc is setup but it's tough to make heads or tails of that top side without dropping it. Its the large single 30+ gallon tank.

Should I expect this to happen or is something not right? Just wondering if anyone has some wisdom that has had one down before?

Any help is greatly appreciated.

 

First, it is definitely not right. They don't leak when full.

It can leak in several place. First is a torn or displaced vent hose. Next is a torn or displaced fill hose. Last is the large bung nut that retains the sending unit. You might be able to feel for the vent hoses. There is one toward the front and one toward the rear of the tank, in each raised bubble area. Those are the most likely issue. You can usually see the fill and overfill vent connections, so you might rule those out just by looking. There isn't much you can do about the bung nut without either dropping the tank or lifting the bed. Unless you have a camper or other stuff in the bed to complicate matters, I would lift the bed. That way you can inspect the top of the tank just as it sits in the hangers. Otherwise, you can drop the tank and do the same thing.

Last thing I can think of is a cracked tank or fitting. Not likely on those.

Here are some pictures to show what you are getting in to.
Powerstroke Fuel Tank Modification

 

wow, ive changed a few tanks before, but cant believe you'd lift the bed over dropping a tank. Is it really easier?

 

One of my friends did it he said it took them 3 guys and was a lot easier than expected

 

Just a word of caution, the bed bolts are notoriously difficult to remove, and if you have to cut them off, the bolts and clips are unusually expensive from the dealer.

 

The nice thing about lifting the bed, is that you can easily look for the source of the leak and see evidence. If you drop the tank you will have to reach up over the top and disconnect hoses and electrical, and that may make it harder to figure out. On the other hand, you might feel the cracked hose right away. But it is not a big job either way, lift it or drop it.

 

I agree that removing the bed is easier.

I did it 5 plus times on my last truck. Dropped the tanks only once and swore to NEVER do it again.

Thad