My factory tank (1970 GS) has a small leak at the front of the tank on the passenger side only when the tank is more than about 1/2 full and only after the car is driven (not when just sitting). I think it has to do with right side tail pipe coming fairly close to the tank and heating the area up. The leak is a very slow drip-drip-drip. So, in checking online there are dozens of leak repair products that claim to stop gas tank leaks without removing the tank. That's for me 'cause I ain't removing that tank again! So, what products have any of you used that work well with very small leaks?
The JB marine weld is fuel impervious I'm pretty positive,...clean,..scuff with 220/180 paper and apply
I would check all the vent hoses and connections. The tailpipe would not be hot enough to hurt anything back there, the tank halves are welded together and the vent nipples are soldered, the tail pipe won't hurt that. Its likely its dripping off the sending unit/lines and running along the seam and dripping off that corner. Thats all but a guarantee if it only leaks when its running.. its dripping off one of the lines.
Ray, I have a leak as well. Mine appears to be in the area of the vent.et us know what you end up doing.
I'm gonna be "that" guy. Replace the tank. You're just kicking the can down the road, but you don't get to choose where it fails and leaves you stranded, or worse, with a smoldering "used to be your pride and joy" on the side of the road, or in your garage ...
On my early’70 Naa, don't think so. The tank was removed last year to install the RobbMC 1/2 in. pickup/sending unit. It was inspected at that time and several of the 3 vents replaced. It was clean inside and showed no signs of rust. I also like to be safe but, a new tank under these circumstances is an overkill IMO. But, thanks for your concern. We'll have it up on the lift on Monday and I'll report back on where the leak was.
I'm not sure exactly how safe this is on a gas tank, but for exhaust leaks I use the reverse shop vac trick: Basically you hook your shop vac in blow mode up to the gas filler neck (or exhaust pipe for exhaust leaks) and then spray the area with simple green or soapy water, look for bubbles to find the leak!
[QUOTE="rkammer, ... It was inspected at that time and several of the 3 vents replaced. It was clean inside and showed no signs of rust. ...[/QUOTE] Gotcha. I was going with "original +50 year old tank, small leak" and thinking pinhole (rust) and where that always ends up.
btw Hirsch gas tank sealer works great on pin holes, but you gotta take the tank out and slosh it around. I believe there are other brands that copied him. It hardens when in contact with gas. https://www.hirschauto.com/Gas-Tank...CLqoce2YXKkpw57cslMy5zJhK7lUVtvAaAgG8EALw_wcB
I can't solve your leak problem, but I too would seriously doubt that the exhaust would hurt the tank. Maybe even the opposite would be true - what heat is transferred to the tank would help dry any moisture. The vent hoses are another matter. I am not a fan of leak stop chemicals. This job kinda sucks, but you should crawl around under the car (unless you have a lift) with a flashlight and if necessary a small mirror, until you positively locate the source of the gas leak. Now you will know exactly what you need to fix. The fuel system is one of a car's killer systems. It is not something to put a band-Aid on.
