Exhaust leak between exhaust manifold flange and turbo flange

[JField]

After replacement of the exhaust manifold with a BD 2 piece stainless manifold, I have a leak between the two flanges that I haven’t been able to cure. It’s been disassembled twice, and gaskets replaced. New bolts and studs. Has anyone else run into this difficulty and if so, what did you do to fix it and in particular, what am I doing wrong.
Thanks for any input and help. 200,000 miles on the clock

 

[Rowdy Dalton]

Pics?

 

[JField]

Pics?

Pics?

 

[JField]

Pics?

It won’t let me download a video

 

[Ozymandias]

Are you totally sure that the leak is between manifold and turbo?
I ask because the connection between turbo and downpipe elbow is very prone to leak.
That one that you mention is a very straight forward connection and it's hard to imagine how this two flat flanges with the tin seal in-between can leak.

 

[JField]

Are you totally sure that the leak is between manifold and turbo?
I ask because the connection between turbo and downpipe elbow is very prone to leak.
That one that you mention is a very straight forward connection and it's hard to imagine how this two flat flanges with the tin seal in-between can leak.

100% sure

 

[Ozymandias]

Then check that BD manifold thoroughly that the flange is really true. That's the only thing that I can think of.
And that the studs are the right one for the application. I had it once that the threads on the studs have been to short and the nut bottomed out before the proper clamping force was reached.

 

[JField]

I checked for perfectly flat surfaces on both turbo flange and exhaust manifold. The only thing that it could possibly be in my estimation is the angle of the BD flange.

 

[BigPapa]

The only thing that it could possibly be in my estimation is the angle of the BD flange.

Not following you on this. If the surfaces are flat, if your gasket is good, is the turbo touching something that’s keeping it from seating properly on the manifold flange? Check the holes in the turbo for debris. You said new bolts and studs. Are they Cummins parts?

 

[JField]

I was thinking that the surface on the BD exhaust manifold is flat but possibly machined canted, where it makes contact on one edge, but not as good of contact on the opposite edge.

 

[Ozymandias]

Stupid question, but you had the connection between Turbo and Downpipe completely loose while assemble that manifold?

 

[BigPapa]

Flat’s flat. Are the studs square with the surface?

You didn’t answer my other questions.

 

[JField]

Flat’s flat. Are the studs square with the surface?
You didn’t answer my other questions.

I have a crack in the exhaust manifold at the mating surface between the two pipe plug holes. Time to replace the exhaust manifold.

 

[BigPapa]

Well, that would explain it. I thought you had just put it on?

 

[Ozymandias]

I have a crack in the exhaust manifold at the mating surface between the two pipe plug holes. Time to replace the exhaust manifold.

That's what I thought and asked for.
My BD leaked at the connection between the 2 half-manifolds.

After that I ditched the whole aftermarket and went with a OEM Cummins from Genos Garage. Problem solved, once and for all.