72 coupe, 4 speed - My drivers side exhaust flange keeps loosening up from the manifold. I can tighten the nuts, and in 10-15 miles, the leak can be heard again.
Anybody have a fix for this ? Metal lock nuts, thread sealer, section of flex hose?
Could a bad motor mount be contributing to the issue, via extra vibration ? The mounts seem to be ok, but I have no idea how old they are.
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Do you have the donut gasket between the exhaust pipe and the exhaust manifold installed?
1973 L-82 4 spd
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Yes, gasket is in place. It was fine for several weeks after new exhaust was installed, then gradually started developing a leak.
After 3 re-tightenings, I think I need to put a new gasket in, because it doesn't go completely away any more. Maybe a new gasket will help. We shall see.
It could be they didn't get the inside nut tightened all the way and the first leak got all this started. When I first discovered the leak, the inside nut was the loosest.
|UPDATED|8/5/2023 2:46:24 PM (AZT)|/UPDATED|
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The gaskets I use appear to be made from a highly compressed asbestos or equivalent material with a steel sleeve on the inside of it. I always assumed that the gasket was to seal the gases in and that the steel sleeve was to protect the gasket from the heat.
1973 L-82 4 spd
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Is there any play in the nuts as they’re threaded on the studs? The diameter of the studs may have shrunk with corrosion over the years. If so, you will need to replace the studs to get enough friction to keep the nuts tight. Not a fun job.
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The nuts don't seem to be loose around the stud, but I am going to replace them when I do the new gasket and see if that helps. Yeah, I would hate to have to pull the manifold off and try to get those studs out. That would probably be a winter job with lots of Kroil involved.
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Just a F.Y.I. on new nuts. Above all else, use BRASS nuts. They will not rust fast to the stud. Much easier to remove.
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Are you using metal lock nuts?
Not yet, I was told they could be very hard to get back off ?
It may come to that, but I am going to try a new gasket and new nuts first.
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Just a F.Y.I. on new nuts. Above all else, use BRASS nuts. They will not rust fast to the stud. Much easier to remove.
I couldn't find any fine thread brass nuts locally, so I put a new donut gasket and new grade 8 nuts in today. And I was careful to get the donut centered and torqued consistently all the way around.
We shall see how this holds.
If nothing else, it might get me to cold weather. Then I can pull the manifold, soak the studs in Kroil for a while, and put new ones in.
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