After searching for about an hour and a half and not finding anything that is close to my issue I thought I would put it out here and see if anyone can guess the issue with out me having to drop the tank.
My issue is when I fill the tank I am leaking fuel for about the first 20 miles. Now here is the kicker, it only leaks when the truck is off, not running. When I park, I have to wait about 2-3 min. then it will start leaking from the top. It will leak to the pass. side and to the rear of the tank.
When I added about 8 gallons last night, I removed the cap to hear the vacuum suck in air. So it is holding pressure.
The truck starts with no problems, I seem to have no other issues but getting 11MPG.
I just bought it 2 weeks ago so I can't compare it to pre-leak.
I have a 95 3.sl0w V6. It also seems that the fuel lines have been replaced with in the last year or so.
Any suggestions will help. And if I didn't use my super searching skills and the answer is out there, please forgive me (and link the post) Thank you for your time.

 

The only way to really know whats going on is to either remove the tank or the bed. I would recommend removing the bed, that way you can run the truck and pin point the leak.

 

Sorry, I forgot to mention it is a 4Runner.

 

Check under the rear passenger seat and see if you have an access panel above the gas tank, if you do then remove it and you will be able to see the top of the tank and the fuel lines.

 

You have a crack or pin hole in most likely the return line and the pressure in the tank pushes it out.

Now if this has never been apart good luck .

the fuel pump brackets if you can find one from the southwest you might be able to get away with a used one.

New from the dealer around $180.00 ** but with the dollar being devalued the price might have gone up.

** This price is off the top of my head and could be way off

 

Either a pin hole leak in the return lines, or a pinhole leak in the pickup on the top of the tank, causing extra air to get pulled through the line... causing a potential lean mixture, and your. 11MPG..