Exhaust Dereg Trouble

[pdxjim]

Ok, now I'm not very happy. I did my exhaust dereg this weekend and now I have a slight leak at the manifold. I'm good with tools and believe in service manuals. I used a Dremel and a carbide cutter to remove the 3 weld beads holding in the restrictor cone. It took me a while, but no troubles. I carefully reinstall the exhaust by hanging first with side bolts leaving them loose, attach the manifold bolts, line everything up, finger tight first, then start torquing to spec. 20 ft-lbs on the side and 9.5 ft-lb at the manifold. Done. I start it up and it seems too noisy. I feel around the manifold and it feels like a leak! I take the manifold back off and I can see the flange isn't flat anymore with my eyes. I know it was before I started because I looked it over carefully before starting. I don't even need to check it with a straight edge because I can see the flange has a bow now.

Bad torque wrench? Should've just hand tightened? Pot metal flange?

Anyone have any ideas what I should do with this flange now to get a good fit with the gasket? I'm trying to think of any clever ways to bend it back. By the way, the gasket is the thick compressible copper type. It's in good shape.

[sooznd]

Have you tried flipping the gasket the other way around? I dropped mine & couldn't remember which way it went in so it has probably been in both ways--It is kind of tricky getting the exhaust and bolts on exactly flush.

[pdxjim]

I'll just fuss with it I guess. I'll post my results later...

[pdxjim]

Okay, I got it fixed. Twisting the gasket around to just the right spot got it. However, I think there's a factory design problem here...the "compressible" gasket doesn't really compress before the flange ears start to bend. Either it isn't compressible enough, or there should have been a separate bolt flange that slips over the exhaust flange to distribute the pressure like on my old Chevy. Either way, it's fixed.

[speedy_scooter]

I'm very surprised that you bent the manifold. Be carefull that it doesnt break off not that its been bent around. Glad that it works though.

[pdxjim]

I'm surprised too. I didn't torque it that much, and when I gingerly tried to see if I could bend it back, I found it very resistant. I'm almost thinking it really was that way to start with. Maybe that's why they use thick "compressible" gaskets...to cover up a not-so flush flange.