I have a 1971 Charger with one million year old headers on it. I knew I had an exhaust leak, but I couldn't find it at the typical locations (flange, collector gasket, etc.).

But today I confirmed with both the rubber hose to the ear trick and with a handheld petroleum vapor monitor that it is leaking somewhere where the four tubes come together into the collector.

I got the header out of the car. I cannot see any holes. I could not find a hole by filling the header with water, or see any light shining through. So I assume that is a pinhole leak of some kind?

Has anyone ever had this experience?

I don't think I can really "fix" it, but is there any repair I could try to get it through until next year? Like a spray on coating of some kind that might find it's way to the hole? I can't see any way that trying to wrap it with muffler tape would work.

Let me know if you have any thoughts or experience with this.

Thank you.

Greg

Make blockoff plates and pressurize/smoke test.

I can't imagine any kind of coating fixing it.

sounds like inside the collector... a hard to get to spot and with rust added in the mix probably a no cure deal.

Time for a new set. They're thin and will keep popping holes/leaking.

I have a set of JR headers that have been on my Hemi street car since the late 70's
I had the same problem, turned out the leak was on the plate welded in the center of the end of the tubes.
I cut a window in the collector. Fixing the leak took less time than finding it.

muffler repair cement---in the old days i repaired more than one cheap a$$ customers exhaust with the stuff

he,he,he. i was going to suggest the same thing ! in fact, i went out and got the old tube of stuff i had to see what brand it was.
Western Auto brand, and there hasn't been a Western Auto store here since the mid 70's.
and just for your information, that tube is HARDER than my HEAD now !
i guess i can't use any of it that's left in the tube .............

There is a part of me that suspects this is where it is, but I am not 100% certain.

I may try to paste it up and see what happens, I wasn't quite prepared financially to fork out for Doug's or TTI this year, that was on next year's list. Will have to make a decision I guess.

Thanks for the help everyone.

Greg

Once headers get to the point of leakage due to rust, i wouldn't throw another dime at fixing them since you have no idea where the next issue will show up. Plus, prices are rising on everything. IMHO bite the bullet and figure out how to get new ones now.

as silly as it sounds, when i run across a nice set of pipes at a swap meet for cheap, i snag them.
i bought a set of beat on 2" to 2 1/8" TTI's at carlisle one year, where someone heated several of the tubes right at the flange and smashed them with a BFH. they were like new otherwise.
took them home and sectioned in pieces of 16ga tubing. like new again and will work for the new engine for my charger !
i bought a couple sets of 2" heavy wall tubes that fit the chassis i built for my 33 dodge humpback panel truck [the "eternal project] like they were designed for it. they were like new. i believe they may have been Appliance brand, because they had a square collector flange, and the pipe flanges at the heads were separated from each other when they were built. i think Appliance was the only ones that did that ? anyway, $100 for one set, and $50 for the other.
at the last fall Canfeild Ohio swap meet, i bought a like new set of B-body 1 7/8" ceramic coated Hookers for $65.
i should have enough pipes to last me for a day or two. [like till i croak. ]
i have even sold a couple sets i bought, and now the ones i have are basically free money wise, but then storing them in the "stuff" can present some "interesting solutions" to say the least.