Cracked exhaust flange

[Jbbishop2]

On my '88 4WD passenger van I've had the exhaust replaced from the catalytic outlet back (pipe/muffler/tailpipe), and later when I noticed there were a couple of upstream leaks I asked the muffler shop to weld those up, too. One was a crack part way around one of the two exit pipes at the flange where the pipe connects to the exhaust manifold. The welder did weld the crack, but he said it would probably crack again as the material around the crack was very brittle, crazed with surface cracks. And, it did, so I still have some part of the exhaust coming out underneath where it shouldn't.

First, is anyone familiar with this condition? It doesn't make a lot of sense to me that steel would do that.

Second, does anyone have a flange and the 2-into-1 below it that I could buy? If I take it to the shop they can build the rest of the pipe off that.

Third, any other suggestions?

Thanks,

John

[ingmire]

If you search 'exhaust manifold' there is some in depth info. I'm going to replace mine soon, the priece that connects to the engine and gasket. It's a big job.

Could be what your experiencing too. Hopefully not

[Burntboot]

JB2 - The downpipe has been NLA for a very long time but any exhaust shop worth its salt, should be able to build a new one.
As long as you have the flange, the rest should be just about tossing money at it.

Back in the day, when we used to do performance exhausts, we used to make custom downpipes fairly often.
Not the most fun thing to do as its fiddly, time consuming stuff.

I have even made custom flanges but never enjoyed that part, too easy to warp and have to start again.

[Burntboot]

And yes, it is "common" condition.

Even under perfectly running conditions, that pipe sees a lot of heat cycling, throw in a little lean or rich condition and the stress is increased and after 30+ years of service, metal fatigue can become an issue,

Used is always an option, but with everything being of a similar age, its getting harder to find viable used parts.