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02 Gmc Sierra Fuel Tank Repair/Replace

So i managed to pop a hole in my fuel tank, a very clean round puncture no cracks. “truck fell on scissor jack”. I Have been looking for a new tank for the truck but all i can find for it is discontinued tanks. I bought some gas tank repair putty from auto zone see link below. I have not tested this repair yet. If this does not hold does anyone have any suggestions on repair or were to find a tank that wont cost me a arm and a leg, looks like junk yards puncture tanks…I had another idea since the hole is very clean almost looks like someone took a 1/4inch drill bit to it clean…i thought about if i can get my arm inside the tank i could take a stainless steel bolt and some type of gas resistant washer on inside and out…thoughts?

P.s If this doesnt leak i plan to spray a entire can of flex seal over this patch to keep it from flaking off and just add another layer of protection.

We do puncture tanks (and oil pans, transmission pans) to drain fluids. But, that tank should be easy to find at a salvage / wrecking yard, I’d think. Or, someone’s probably parting out a Sierra or Silverado on Craigslist in your area and would sell the gas tank cheap. You’d probably have to pull it yourself if you went the Craigslist route.

Yea all my local scrapyards puncture them and i don’t have many as its a small town.

You should be able to get your arm into the tank through the fuel pump access. It is on top of the tank toward the front of the truck. You can get at it by either dropping the tank or loosening the8 bolts holding the bed down and sliding the bed to the rear. You’ll need a couple of friends to help you with that.

That’s a tough one you got there OP. Working on installed gas tanks scares me, so I’d be inclined to replace it rather than trying to do any sort of complicated repair requiring access to the inside of the tank . Hopefully the seal-leak product you’ve already applied will do the job.

I have used epoxy to repair many tanks, always worked well. The best I ever used was made by Napa, had a wax crayon to plug the leak and a tube with in a bag setup for the 2 part epoxy.

You broke the tube and kneaded the bag to mix the epoxy, cut the bag open and spread the epoxy on the tank. It would work on a hole in the bottom of a full 60 gallon diesel tank and the epoxy would grab right through the diesel fuel. You didn’t want to get any of that stuff on your hands.

If it worked that well either the government will have outlawed it due to some chemical in it or the manufacturer will have discontinued it because working right the first time will hurt sales. After all why fix something once when people will pay to fix it repeatedly.

I suspect you’re probably right

I don’t know about any of the other states, but here in California, it seems none of the brake cleaners or engine degreasers that actually do their job well are available for sale anymore

Update…it worked. I have been watching it since saturdays so 4 days so far and not a single drop of fuel coming out. Im going to go ahead and spray some flex seal around the patch as well to help protect the patch itself. I know if it ever does leak past the patch the flex seal is pointless but flex seal will be just a layer over the patch. Truck is back on the road time to put another 300k miles on it lol.


Congratulations, thanks for letting us know! Enjoy the next 300k!! :smiley: