jon_7248

Well, my old 4Runner had a leak on the top of the gas tank. Now I know a temp solution of the bar of soup, but thats a trail solution, not a true fix. Anyone know of any ways to fix a leaking gas tank? It only leaks when full. I thought of JBweld untill I get some monies to get me a new tank, perhaps even a bigger one under the rear where the spare tire would go. Wouldnt mind having a bigger tank.

mastacox

Where is it leaking from?

jon_7248

Thats a slight problem to describe. My brother has the truck and is bringing it up on a trailer this Saturday. At present I only know how he describes it. He says that there is either a slight rust hole up top, or a seal that isnt working from up top. Now I know nothing of the gas tanks as to where the filler tube taps in, fuel pump or anything else so I have no idea if there is something that is connected to the top, or if its rust.

mastacox

I would drop the tank to find out. Could be you have to replace a seal or a few rubber lines, or it could be you have a rusted hole in it and need to replace the whole thing.

jon_7248

Know how thick the tanks are? Wonder if I can just drain all the fuel out to clean it up, and weld the top hole closed, im cheap

mastacox

If your tank has a rusted hole in it, I would say it's beyond help of most any kind... plus all that rust may have started getting in your gas too. But, I would guess you have a cracked line or leaky gasket.

SacRunner

If you drop your skid plate you'll see a drain plug that looks identical to an oil drain plug, use that to drain the tank, no need to add any more holes to it.

The tank walls really aren't that thick, and there's lots of flat spots on top of the tank where water can accumulate (very small amounts, but enough) and allow the tank to rust. The whole tank completely empty weighs less than 20lbs.

I had a similar problem with a crack on the bottom of my tank and tried using some eppoxy to fix it, didn't work too well, so I paid $150 for a "new" tank from a junk yard. If you do get a new tank, make sure it's from the same year, or REALLY close, I have a '91 4Runner and a tank out of a '95 4Runner was a good 3 inches deeper (top 1/2 is identical, just a deeper bottom 1/2).

what ever you do, be carefull, getting the tank in and out, its a tight fit. If you do decide to weld on it...be super carefull and make sure all the vapors are out. I have no idea how to do this but you don't want the thing exploding on you.

-everything i said is based off my '91 tank, the '95 tank i tried and eventually the '90 tank i ended up with (all 4Runners) so your 87 may or may not be different.

jon_7248

Oh I would prolly let it set outside for a day or two before I go near it with the welder. Im hoping it's a seal leak and not a rusty hole, but when I gave it to my brother, it did sit for a year with no use so who knows.

rebult junk

flush the tank with water over and over and over and over the brazing rod is the way to fix the a small hole in a gas tank
make shure the tank is flushed out well

Toy-SkiTzo

i had the same problem and it ended up being the sender unit rotted threw

Elvota

Welding or brazing a gas tank is nothing to guess at. Make sure you have a complete understanding on how to purge the tank of fumes before you start.

The learning curve on a mistake there is sharp and painful. :fireman:

bruzer1123

I had a similar problem on my '87 pickup and my '93 pickup-I am blaming the salt and rust of New England-and both times it ended up being the fuel pump bracket that comes out of tank. The return line was shot and leaking out of that. If you are looking for a temp fix you can just cut the rotten line out and replace with rubber, or if you can braize...take the bracket out and put new lines on...or you can just buy a new bracket. Good luck

neilan

hmm well i have a complete 87 tank minus the sending unit i have bene tryign to get rid of to someone who needs it. I was tryign to get a couple bucks for it and it prob cost around 30 to ship but ill put it out there. I bought the whole tank asembly to get the sending unit so thats all thas missing. It still has the fuel pump and whatever else is in there lol

91TPU

i had the same issue...

as for welding the tank, gas tanks have a special coating on the inside, and i beleive when they are worked on they have to pass a certification afterwards...ofcourse, if your welding it yourself you wouldnt have to worry about any of this, but man, if all the fumes/gas arent out, your gonna be one sorry guy.

jon_7248

Well, I just picked up a new tank for an AUX tank recently, wish I new sooner.

jon_7248

Im hoping it's not a hole in the tank, and I think it's not a hole as well. I filled it up full the other day and nothing spilled out until the next day when I noticed it while I got in the other car to go to work. Since then I hanvt seen any leaks, but I also have the tank about half full or less.

The gauge is funky. If I fill it up it's normally full, but it drops fast and drops all the way down on the dial even though it may have 10 gallons in it. Any thoughts?

toyota_mdt_tech

Yes, a product called "Seal-All" and you can buy it from Home Depot. I saw this stuff work first had years ago, was recommended for a fuel leak on the bottom of a Ford gas tank. I took a dab on my thumb, pushed it up on the fuel leak, while it was leaking, held it for a minute. And that was it. It never ever leaked again. And it sealed it while it was leaking gas. It comes in a tube. It exactly what you are after!