Leak from Fuel tank

[BUDFIVE]

I put another 10 gallons of gas in the tank for my next go cart. Bummer, A couple hours later I had a small fuel puddle on the shop floor. I can’t recall but his may be the first time I had more than a 1/2 tank in my build (3/4 now). Anyway, after looking a bit I think I found it-the 3/4” down tube meeting the tank flange at the PS rear of the tank appears to have punctured the tank (arrow) where the tank rises from the flange.. The plastic plug is missing from that down tube bottom-perhaps it fell when I lowered the tank a while ago.
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My plan is to pump out most of the fuel and lower the tank, repair it, work on remedying the interference (including plastic plug) and re-raise the tank. Have any of you tried JBWeld Tankweld?

[danmas]

Sorry to hear that you have a leak. I messed around with my jeep gas tank a half dozen times trying to fix valve issues and leaks. Ultimately I replaced it since I really didn’t want fuel dripping or the associated problems with filling. Probably some of the experts here have a differing opinion but for me I don’t want leaking combustibles or worrying about it. Good luck!

[Blitzboy54]

FYI the kit comes with plastic caps that go into those 4 tubes. From your picture it doesn’t look like they are installed.



**Edit** I read this at 3:00am when I couldn't sleep. I didn't read it very carefully and missed that he said that they were installed. Was quoted so will leave it.

[Nigel Allen]

It might be safest to buy a new tank.

[egchewy79]

As much as I hate to spend money unnecessarily, I think that this would be $$ well spent. If nothing else to have peace of mind that fuel won't be leaking from there in the future. You could always drain/drop the tank and find someone to weld it, but be darn sure that all the fuel vapors have been evacuated.

[weendoggy]

FYI the kit comes with plastic caps that go into those 4 tubes. From your picture it doesn’t look like they are installed.

I think he mentioned that already.

[BUDFIVE]

Nigel, Egchewy, I might just replace the tank, is it just a 15.4ga foxbody mustang tank?
I was curious if anyone had tried the JB TankWeld-videos seem to show it does?

[phileas_fogg]

If you can't verify the leak came from where you think the tank is punctured, check the O-ring seals under the fuel level pickup and the fuel pump. If you used sealant (as shown in the F5 assembly videos), you're pretty much guaranteed to have a leak; the sealant gets hard & brittle, and doesn't allow the O-ring to seal. The solution is to replace the O-rings, using a drop or three of motor oil as lubricant to keep the seal from tearing as you tighten the retaining ring.


John

[gbranham]

As others have mentioned, a new Fox Mustang fuel tank is in the neighborhood of $200. That's your best option if the tank itself is indeed leaking.

[Nigel Allen]

Nigel, Egchewy, I might just replace the tank, is it just a 15.4ga foxbody mustang tank?
I was curious if anyone had tried the JB TankWeld-videos seem to show it does?

Sorry, don't know Mustangs well, as they weren't sold in Oz in that era. I'm sure others can chime in with the correct spec.

Cheers,

Nigel

[J R Jones]

I expect the JB Weld concept applies to a hole on an open, unstressed surface. I would not rely on JB Weld or any chemical to seal fuel. Fuel is a dangerous fire hazard.
I question the design. I would eliminate the interference no matter how you fix the leak. How long will a plastic plug last in the circumstances I see in your photo?
jim

[Blitzboy54]

I think he mentioned that already.

Yup, definitely missed that. Sorry

[egchewy79]

Nigel, Egchewy, I might just replace the tank, is it just a 15.4ga foxbody mustang tank?
I was curious if anyone had tried the JB TankWeld-videos seem to show it does?

yes, 15+gallon foxbody is what you want. as mentioned, the pickup and sender areas can leak, so make sure that's not the area first. Usually they don't leak until the tank is full as they are at the very top of the tank. Could also be from the filler neck grommet as well. Kit-provided grommet is known to crack very easily so OEM replacement is prefered. No experience w/ JB weld in this area. I'd drop the tank first to make sure that it is leaking where you think it is before doing anything else.

[Norm B]

That vertical 3/4 frame should land directly on the flat flange of the tank and not touch the tank wall. The plastic cap would only provide protection for a short time the way it is now. The tank may be repairable if that is the source of the leak. Cost of repair might equal the replacement cost. JB weld in that location probably won’t last.

Norm

[rich grsc]

Do you want to trust your new car, or your life to a JB Weld repair?
Norm is correct the leg should not touch the tank wall, only the flat of the flange.

[BUDFIVE]

I emptied and dropped the tank today. The plastic end was on the tube bottom but destroyed. While deformed at the post bottom the tank didn’t puncture. The orings at the pump and sender openings are not leaking. It is leaking between the pressed/welded halves (finger). I ordered a new tank-only about $120 at Summit.

I bought some new tube bottom plugs. If the down tubes (front and rear) are too close to hit on the flats of the new tank (as Norm said) I can bend one or both a bit.

Thanks for the input y’all.
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[Windsorpower]

yes, 15+gallon foxbody is what you want. as mentioned, the pickup and sender areas can leak, so make sure that's not the area first. Usually they don't leak until the tank is full as they are at the very top of the tank. Could also be from the filler neck grommet as well. Kit-provided grommet is known to crack very easily so OEM replacement is prefered.

You got a source for that OEM grommet? Most Ford dealers laugh at me when I try to order Fox-body parts for one of my other cars. Also received Chinese garbage when I ordered a throttle cable from 5.0 Resto.

[gbranham]

I got mine on Amazon. Part # F4ZZ9072DA.

[steno]

On my build I also put some rubber sheeting between the plugged 3/4" square tubing and the tank just to be sure.
Just a thought.

[BUDFIVE]

Thanks guys, I installed an OEM fill neck seal with the original tank. I should be able to move it over.

[stuchman1]

Did you get the original fuel tank from FF or source it yourself? If it was FF, I see your car was delivered barely a year ago. Seems like a manufacturing defect that FF should address for you. Tank puncture is one thing, but correctly welded seams shouldn't leak especially when they're barely a year old, I'd think?

[BUDFIVE]

Stuchman, Yes, it was the FFR supplied tank. But the seam it’s leaking from is right where the seemed lip curls up and we bend it flat by the straps to meet flush with the 3/4” down tube with plastic insert. It’s impossible to tell if the seamed lip would have leaked before I bent it. So I view this as just one of those integration failures that happens during a build. I’ll make that bend on my new tank as carefully as I can and hopefully it wont leak.

For reference, when the high side power steering hose separated at the AN fitting during install FFR took it seriously, shipped a new one to me, and checked their stock to make sure it wasn’t a recurring problem. Good on FFR for that.

[stuchman1]

For sure - FF is very responsive and owns it when issues are brought to their attention. Glad it has worked out for you!

[kevin j sullivan]

Best to just get another tank, (about $225.00). Do yourself a favor and remove the crappy Styrofoam end piece from the float inside the tank. Mine came off twice - floating freely in the tank, clogged my fuel line and shut me down. Don't worry, the fuel gauge still will work perfectly. Put a $15.00 inline fuel filter outside the tank.

[BUDFIVE]

Update—I replaced the tank this weekend with a new Summit-branded Mustang tank. I detailed the
Install in my build thread last night.

https://thefactoryfiveforum.com/showthread.php?47734-BUDFIVE%92s-CenTex-Build-Fuel-Tank-Replacement/page3

I was much more careful bending the tank seam and fitting the 3/4” down tubes this time. Yesterday, I hadn’t seen any leaks after 24 hrs with 5/8 tank of gas. I consider this closed unless I see leaks during/after GoCart 3.0 which is to double check all the mods since 2.0, and have some fun!
Thanks for help.