Broken header flange

[awolff280sl]

When I went to remove my exhaust for subsequent stainless, I found that one of the flanges has been broken off, probably has been like that for more than 20 years. The exhaust was still held on snugly by the remaining 2 bolts.



Since I do not envision taking off the exhaust header, I called a TIG welder who says that he has experience with this sort of problem, as well as with working on cast iron.
In the meantime, I want to ask the group for any ideas. Thanks.

[114015]

Ouch ...,

Andy, the best is to take it out carefully (with lots of penetrating oil) and try to get it welded.
Alternatively & additionally you can look for a pair of decent replacements (250/280 SE sedan).
Especially the rear one is prone to breaking (I was told), and both are heavily overpriced new.

http://www.sls-hh-catalogue.de/bin/dbframes.phtml?mid=IN02

Good luck!
Achim

[Jonny B]

I had a crack in my exhaust header and the machine shop tried to repair with no success. They just kept chasing the crack around the pipe. I ended up purchasing a replacement, fortunately a few years ago, before the prices headed up. I also kept an eye open on ebay and found a pair as spares.

[awolff280sl]

After reading about these misadventures, I'm biting the bullet and going with replacement. Found a used that I'll clean up and then spray and bake with VHT paint.
I've never removed the intake or exhaust manifolds so this is new to me. Besides replacing all the nuts, washers, bolts and gasket with new, please tell me what else to look out for. I understand that removing the old rusted bolts can be quite difficult.
Thanks.

[awolff280sl]

Got all the manifolds off, luckily much easier than I expected.
Questions, please: Do I use any sealant on the manifold gasket?
                   Torque on the nuts 40ft/lbs? (as per prior post)
Thanks.

[jacovdw]

quote:Originally posted by AWOLFF280SL


Questions, please: Do I use any sealant on the manifold gasket?

Andy, there is no need to use a sealing compound if you use a new manifold gasket.

[glennard]

I've got two I can't get apart.  What's the secret?

[waqas]

quote:Originally posted by glennard

I've got two I can't get apart.  What's the secret?

Get apart from the head?  Never had an issue with that, as any wiggle of the intake manifold will usually separate the exhaust manifolds too. (once all nuts have been removed)

Get apart from the down pipes?  Ja17 once gave me the pointer for this: (before removing the entire exhaust)
- douse flanges with your favourite penetrant
- remove all flange nuts and bolts
- disconnect ALL rubber donuts so the entire exhaust simply hangs there
- grab the exhaust pipes from the back of the car and use the entire exhaust as a lever
- move left and right, and wiggle strongly
This procedure has never failed to loosen the pipes from the flange...