Removing the gas tank and fixing hole, FZJ80

[Brian894x4]

OK, so I made a colossal mistake and it’s pretty darn embarrassing to have to fess up about it, but I need some advise.

Basically, I used some short screws to bolt a box to my driver’s side passenger floor and the fuel tank was closer to the floor board than I realized. Apparently, it’s right up against the floor board. These screws were only about 1" long. I should have known better and I'm kicking myself up and down right now.

The hole I made is extremely small, but it’s enough that it needs to be repaired and that means dropping the tank I’m sure.

So, my questions are does anyone have any advise regarding dropping the tank? I can see the exploded diagram in the manual and my thoughts are draining the tank using a drop in hose into the fuel filler (I don’t want to undo the plug if I can avoid it) . Then undoing the fuel filler rubber hose, then unbolting the sending/fuel pump unit from the tank, pulling it out of the tank and leaving it hanging up by the body as the tank drops down.

Looks like there’s some gaskets I’ll have to replace as well. Maybe put a few fuel filter in, since I’m already there.

Does this sound like a plan? I’m afraid I’m overlooking something. My biggest concern is dropping the tank and how heavy it might be.

Finally, once the tank it out, what’s the best way to fix the tank. It should be just a very small hole. I’m wondering if I should use something like JB weld, or RTV or some combination or is there something better? Once I get the tank out, I want to do it right.

Thanks, I'd appreciate any advise.

 

[cruiseroutfit]

You can access the pump setup in cab (under seats), might be easier to drain that way than through the fill tube?

Other than that it sounds like your in the right track... I've never dropped an 80 tank so I'm not much help there.

 

[burl40]

Sorry to hear about the tank mate.You can get the fuel out with a siphon and dropping it should be pretty easy.You can use a floor jack and a small square of plywood to support the tank as you ease it down after you undo the retaining hardware of coarse.Then as far as the hole the best thing to do would be have it welded but I would personally use jb weld not rtv...But that is me I like the easy fix and if the hole is small it should not be a problem......:gunt:

 

[Christian P.]

don't worry it happens to all of us...

if there is a drain plug I would just use it - that's the easiest way to empty the tank. Not sure why you would want to avoid it.

You really want to remove as much gas as possible so it's easy to drop the tank and you don't splash fuel all over after you disconnect the various pipes and hoses. Even just 1 or 2 gallons left in the tank will make the job more difficult.

it's not too hard to drop the tank, but make sure you work in an open and well vented area.

 

[Brian894x4]

The reason I was avoiding the tank drain is that I've heard it tends to start spilling out and spraying everwhere as soon as threads are loosened and I dont' want gas everywhere.

I have a plan B that looks like it might work. I widened the hole in the floor sheetmetal a bit for a better view of the hole in the tank and the tank hole is extremely small. About 1/16th an inch. So, I'm going to try to effect a repair with some gas tank sealer and that might do it.

I have some some tank sealer in my emergency kit that I never really looked at until now or maybe there's a special RTV that might work. I do some research, but any suggestions would be appreciated.

 

[Grim Reaper]

I once watch a guy weld a fuel tank and it was FULL to the brim and the leak was on the bottom!

While he was headed to the tank with welding torch in hand I was running the other way.

Didn't explode.

The danger is the fumes not the liquid. With a slap full tank with no air it the only danger was a fire BUT that was controllable.

What he did is took some soap to temporarily seal the leak. Had the owner go fill the tank till it was in the filler neck. Got the car back put it on the lift and rinsed any fuel residue off. Had one of his guys stand there with a fire extinguisher just in case. Hit it with a few tacks and it was done.


Personally I would weld it and with it being at the top of the tank I would remove the tank fully drain it (cause I still Chicken ********). Fill it with water to displace any fumes and weld it. I have also heard that you could fill the tank with inert gas by sticking a hose on a exhaust pipe to fill the tank with CO so there would be no O2 present to facilitate an explosion.


Now the reason I would weld is simple. I would NEVER trust anything like JB weld to hold. The draining of the tank would also let you clean it out and put a tank sealer in it. The tank will have a sealer and its biggest point is to prevent rust. Rust in the top of the tank is a bigger problem. In the bottom of the tank a spot were the sealer has failed (and it will fail from the heat of welding) is covered with fuel most of the time so it doesn't get the O2 needed to corrode at any sort of rate. In the top you will get condensation and rust will result if you do not have it sealed.

http://www.aircraftspruce.com/menus/cs/fueltanksealants.html
http://www.eastwoodco.com/jump.jsp?itemID=382&itemType=PRODUCT

You might be able to access that spot through the access hole once the pump is out and only need to spot seal where the existing coating was damaged.

 

[Desertdude]

have you considered a machine screw and petroleum resistant washer/gasket ?

You just want to plug the hole, and this can be accomplished right from the top through your vantage point. You'll also be able to check it down the line to see how its holding up.

 

[DaveInDenver]

I basically agree with Grim and Dude, do it right by filling it with water and welding it or whatever other permanent means might work. Last thing you want is the JB Weld or RTV repair coming loose and causing a leak, fire or just plain stink out in the middle of nowhere. I would also take the opportunity to clean and paint everything, replace hoses, in-tank filter and everything. Don't get the chance to do this very often.

 

[UK4X4]

Do it once...do it right.........

If you can access the hole from above........then why take the tank out at all.


Empty fill with water and weld in situe.

JB weld /screw with a rubber washer are all great trail fixes.......

but for me the gas tank is a pretty important part of the truck....

 

[Desertdude]

isn't the gas gauge assembly held in by screws/gasket?

I don't see it as a trail fix, just a way to fix a simple error without making too much more work, or breaking anything else in the interim. It is after all on the top...

Maybe call Slee and get a new tank

 

[Brian894x4]

isn't the gas gauge assembly held in by screws/gasket?

I don't see it as a trail fix, just a way to fix a simple error without making too much more work, or breaking anything else in the interim. It is after all on the top...

Maybe call Slee and get a new tank

Slee sells new tanks? Well, I could use this oppertunity to replace it with that MAF 38 gallon tank....if they were any good and got positive reviews.

No, I think I'm going to try the easy way first. After seeing how small the hole is and where it is, I think I can repair it through the floor, by widening the hole in the floor.

At this point, I'm trying to decided if I should just use gas tank seal puddy by itself or insert a screw as well.

My plan is to fill up extremely small gap between the fuel tank and body with some gas resistent RTV (if I can find some) and create basically a donute around the hole. This will be a last chance barrier. Then I have some permetix permanant fuel tank sealer that is meant to seal leaking holes in gas tanks, which this is not, so it should work just fine. That will be inserted into the tiny hole. I'm not just sure if I should leave it at that, or use a small screw too.

The danger of inserting a screw with sealant is pushing sealant into the tank and the screw working loose or rusting and causing damage later. The danger of the sealant alone is that it breaks down. I don't think it will fall out, because it will be under pressure from the floor when I'm done.

I'll take some pics of my stupidity if I can remember.

 

[adrenaline503]

isn't the gas gauge assembly held in by screws/gasket?

I don't see it as a trail fix, just a way to fix a simple error without making too much more work, or breaking anything else in the interim. It is after all on the top...

I am going to agree with Desertdude on this one. I know my tank uses screws and gaskets, so why not. Just take a peek in a few weeks, if it doesnt look good try something else.

 

[Brian894x4]

One of the arguments against a screw/gasket is that the screws used to hold on the assembly cover and other stuff has more metal to bite as there's inserts for the screws.

In my case, I'm dealing with just the very thin metal of the top of the tank and not the top rise, where the assembly bolts in as that would probably be stronger, but the lower rise towards the front. Probably the weakest part of the tank, if there is such as thing, since it only has to hold vapor pressure and not much else. There's not much for the screw to bite into, so it could potentially work its way loose.

What concerns me is that if the screw or any fix does work its way loose, I'll have gas fumes and maybe fuel itself leaking out of the top of the tank and possibly over towards the exhaust.

But the tank being so close to the floor might work in my favor as the floor could hold in any sealant making it impossible for it to come out.

 

[AndrewP]

Slee sells new tanks? Well, I could use this oppertunity to replace it with that MAF 38 gallon tank....if they were any good and got positive reviews.

No, I think I'm going to try the easy way first. After seeing how small the hole is and where it is, I think I can repair it through the floor, by widening the hole in the floor.

At this point, I'm trying to decided if I should just use gas tank seal puddy by itself or insert a screw as well.

My plan is to fill up extremely small gap between the fuel tank and body with some gas resistent RTV (if I can find some) and create basically a donute around the hole. This will be a last chance barrier. Then I have some permetix permanant fuel tank sealer that is meant to seal leaking holes in gas tanks, which this is not, so it should work just fine. That will be inserted into the tiny hole. I'm not just sure if I should leave it at that, or use a small screw too.

The danger of inserting a screw with sealant is pushing sealant into the tank and the screw working loose or rusting and causing damage later. The danger of the sealant alone is that it breaks down. I don't think it will fall out, because it will be under pressure from the floor when I'm done.

I'll take some pics of my stupidity if I can remember.

I would do this right. Remember the tank gets pressurized in use and any fix that isn't perfect will not work. Plus 6 months from now when it starts leaking again, or won't hold pressure or burns down your house, you'll be pretty unhappy.

Just take the tank out. Drain it first through the drain plug at the bottom, undo the electrical connection, The hoses and the fill/vent. Buy new fill and vent hoses from Toyota when you reinstall. They get very hard over time and difficult to work with. If you had the fill hoses in hand when you started, you could easily do this in a day. With the tank on the ground you'll have more options, including the best one of welding up the hole to restore the tank's integrity.

 

[adrenaline503]

I forgot that the tanks were under pressure in use.