Exhaust pipe welds

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Apr 19, 2017 | 09:11 PM

blanman61

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Exhaust pipe welds

Have had my 78 for about a year & have been plagued with exhaust fumes. PO had just had new exhaust (true duals) installed, pipes still look brand new. Got car up on stands today was going to start with making sure manifold to pipe connections were good with correct gaskets etc. Found that the pipes are welded together in three places and on each weld there is putty/epoxy or something. It is flaked off in places and the welds I can see look crappy certainly not a professional looking bead. What can I do to make sure these connections are not leaking. Don't want to put on new exhaust if there is a reasonable fix.

Apr 19, 2017 | 10:58 PM

TimAT

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With it running, feel around for exhaust leaks at the welds. A better fix would be those wide band clamps around the joints.

Apr 20, 2017 | 05:28 AM

Antz81

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Quote:

Originally Posted by TimAT

With it running, feel around for exhaust leaks at the welds.

Or you could try to listen for a leak using a small tube. one end at your ear, and move the other end around the weld. you should be able to clearly hear if it is leaking.

Apr 20, 2017 | 07:35 AM

71 Vert LS1

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Typically if you have a weld that is leaking there will be some carbon deposits where it's leaking.

Apr 20, 2017 | 10:20 AM

blanman61

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Found the wide clamps, thanks TimAt. The weld joints are uneven, some sealing material wrapped around the joint then clamped with the wide clamp would make a good seal. What would be a good material for this. Saw different wraps for heat shielding, would these make for a good seal?

Apr 20, 2017 | 10:32 AM

69Vett

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"good seal", ... reweld the connection, unless your name is Bubba.
drop the exhaust, clean and reweld.

Apr 20, 2017 | 10:42 AM

7T1vette

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Just take it to a LOCAL muffler shop (not a national chain store...they will rip you off!). They will clean off the cr@p and smooth the existing welds, then finish the job right. Won't cost you much and will be well worth it (rather than to try 'plugging' the leaks).

Apr 20, 2017 | 02:27 PM

Richard454

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Quote:

Originally Posted by 69Vett

"good seal", ... reweld the connection, unless your name is Bubba.
drop the exhaust, clean and reweld.

EXACTLY!!!

I have a friend who got carbon-monoxide poising from a poorly welded exhaust system in his 68 Caddy convertible. It really messed him up for a while.