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I noticed my 1987 4runner has a leak in the bottom part of the gas tank. I can see where it's coming from and it appears somebody tried to fix it with some kind of putty (the putty is moist and dripping gas).
What's the easiest way to repair this?
Some kind of JBWeld/Epoxy?
Take it to a shop to get welded?
Or replace the gas tank entirely? If so, how hard of a project is the later? Is there a DIY anywhere?
Depends on whether the hole is from corrosion or it got a stick jammed through it. Either way, you are going to have to remove it. You can't "shouldn't" weld on a 30 year old gasoline container without it being thoroughly cleaned and properly vented. I'm voting for a "new to you" tank.
I'm sure there are plenty writeups but it's pretty straight forward. 6 skid plate bolts, 6 tank bolts, electrical connector and the filler tube and it should come down easily with a floor jack and maybe a board under it. I was about to warn you about rusty bolts that might break off but I see you are in NM so that shouldn't be a problem. If you do have some rust under there, start soaking them tomorrow with some penetrating oil and keep doing it every couple of days while you track down a tank. Oh and soak down any fuel line fittings. Those things can be tough a lot of times.
It's pretty easy. Drop the skid plate then remove the fuel filler in the door. I did one in my 86 and there is an access panel under the passenger rear seat to disconnect the electrical and fuel lines, then drop the tank. I think it's a total of six bolts on the tank and six on the skid plate? At least you don't have to worry about draining it. Tony
Just thought of something. How big is the hole where it is leaking? Could you drill it our round and have it tapped for a drain plug? That might come in handy at some point.
@Charche, that is a good idea. On another forum I read of somebody fixing a gas tank leak with a self-threading bolt and an o-ring. So maybe that would be an easy thing to try out first.
However, I don't know the size of the hole yet. The hole is covered with some kind of sealant and I don't want to peel it off just yet. The leak is pretty minor (a couple of drops every hour), so I'm going to use the truck until the gas tank is near empty, then deal with the situation.
I am attaching two pictures to give you a better idea.
The first one is a picture of the gas tank from underneath. I'm confused by some of the instructions on here, as it seems like there is no skid plate. Am I missing something?
The second one is a picture of the leak. You can see where I peeled off about the bottom half of the putty-like material that's sealing it.
Yours sure is gone. No doubt removed when the PO put the sealant on there. The skid plate sits real close to the tank in that spot. I bet a limb or something got hung up between the frame and the skid plate and bent it in to the tank. After a bunch of vibration between the two, a hole developed. That's my theory. The metal is likely going to be very thin there due to the rubbing, if I'm right. I'm going to get beat up over this but, if you got that tank empty and you cleaned the you know what out of that spot, you may be able to use a product like what's on it and make it work. Come ride with me for a day at work and I'll show you a dozen diesel and hydraulic tanks patched that way and haven't leaked in years. If it is rubbed through there, I'd be afraid to weld on it but it would be best for you to show it to maybe a exhaust shop before you run out of gas and see what they think.
Just to be clear. It is a gas tank and any hot work on it is extremely dangerous. You know that but there it is in writing.
Drill it out and install a bulkhead type bolt, that is essentially a bolt a washer an o-ring the tank wall another o-ring another washer and finally a nut..
Brazing or welding it will be the same process, drain it, fill it with water, the seal it off..
For a JB weld you'll want to provide a mechanical attachment also for more bite. This could be just a few self tappers or screwing a plate over the patch material..
All of which are best done with it full or nearly full of water. Unless you go with the diy approach it will likely be cheaper to source a new or used tank.. welcome to our disposable society :sadpanda..
It kind of looks like factory seam sealer from here. Make sure you clear off extra surrounding area. Also you'll want to reseal the inside of the tank with redcoat or another brand tank sealer, which is going to require a clean dry tank and several days to cure...
I never thought of filling a gas tank with water. That takes all of the explosive vapors out of the equation. Good idea.
I've been extra cautious the last few years after I went out to assess damages to some equipment I had rented to a refinery. A couple guys were grinding on a old empty fuel tank, some kind of LP, when it exploded, killing both of them and completely destroying three pieces of heavy equipment. They said the fuel had penetrated so deep into the metal that after it was empty, the saturated metal filled the tank with fumes.
I never thought of filling a gas tank with water. That takes all of the explosive vapors out of the equation. Good idea.
I've been extra cautious the last few years after I went out to assess damages to some equipment I had rented to a refinery. A couple guys were grinding on a old empty fuel tank, some kind of LP, when it exploded, killing both of them and completely destroying three pieces of heavy equipment. They said the fuel had penetrated so deep into the metal that after it was empty, the saturated metal filled the tank with fumes.
yep, even a clean dry looking tank can fill with explosive amounts of vapor when heated.
Water makes brazing difficult but it's doable with a small air space and much less risk. It can shock a weld and induce cracking, nothing some preheat shouldn't solve.
On topic, the JB weld under a patch panel is the easiest and a safe alternate in place repair and plenty durable.
ymmv. i've had good luck repairing holes and pinholes without tank sealers. i've had no luck repairing tank leaks along the seam that joins the tank halves.
02-18-2017, 03:26 PM
