Exhaust Leak Help Needed

I’ve replaced the gasket between the exhaust header and the downpipe and I’m still getting a leak. I’m had it off many times tried some different sealants but it leaks on both sides. I’m afraid to tighten it up anymore I don’t want to snap the stud off in the cast-iron header
Is there a donut style gasket that might work better at sealing it?
I’ve search the forms but came up with nothing. Thanks for any help

 

F134? Always post year/model/equipment with your question, or put it in your signature file.

So it has a flat gasket from the factory, and you are using it in the factory manner? If it leaks, that means the flange or the manifold face is not flat. I'd take it loose, and get down there with a machinists ruller and measure those parts for flatness.

 

As Tim suggests info. and pictures would help, without that it is simply guesses to what you have.

Is this like the down pipe you speak of? And, if so is that where it is leaking?

 

Maybe a misalignment in the exhaust pipe is forcing the gasket surface out of parallel contact... ?

You could try bolting it up at the manifold with just the down-pipe floating free, and the rest of the exhaust disconnected. If the down pipe doesn't align with rest of the system at it's tail end, heat and bend them until the joints all align without distortion or stress.

 

My F134 Application. I had the same issue. Eventually had to remove the exhaust manifold so I could work on it. What I thought was clean, once I removed the manifold there was old gasket build up that needed cleaning. "Project creep" as usual

 

I made a copper gasket the same as the flat gasket. I’ll probably try a flat gasket on each side of the copper gasket and see if that works.
Thanks for the ideas, I may have to try some heat.

 

Your TSM will have a torque specification for the flange nuts. Also, your local muffler shop can remove any broken studs in situ with the oxyacetylene cutting torch. They'll heat up the broken stud, and one touch to the O2 blasts the stud out. Sounds strange, but I've seen it done. Supposedly quite common.

 

Hopefully I don’t break the stud. I do have a local muffler shop close by but I’m being stubborn and trying to figure this out myself

 

That sounds interesting I’m going out to the garage now and see what I can come up with.

 

Made a bottle holder (or beer can) for this Jeep

 

Back together with a sleeve, copper gasket with regular gasket each side. High temperature RTV silicone between each layer. Will let it cure 24 hours and see if it works.

 

Rather than hi-temp RTV (which I'm sure will not survive more than a few minutes), I have used this stuff
https://www.amazon.com/Dynomax-3595.../B000CQHVLI/ref=sr_1_3?keywords=exhaust+paste
and it worked well. Actually I used the Permatex branded stuff, but it's the same material AFAIK.

 

Maybe you should take the manifold off and check it out for flat, it may need to be ground flat??? I had to drill out three broken studs in my head and replace them, I used brass nuts and anti seize on the threads this time. Good Luck

 

Ok I’ll get some muffler cement, thanks for the tip

 

Sealants and goo are not the answer. As posted above you either have misalignment, something is not flat or a cracked manifold.

 

x2.

 

If it doesn’t look like this pic, as Howard says, it’s not gonna work right.