Removing Rusty manifold exhaust bolts

[dickeymoore]

I have a 1980 Chevy Malibu with a small block Chevy V8 engine and I need to remove the exhaust manifold Bolts from the pipe to the end of the manifold but they are really rusty what is a good way to remove the bolts without breaking them off into the manifold flange

 

[TURNA]

Heat or soke them in PBlaster

 

[buick7332]

I have a 1980 Chevy Malibu with a small block Chevy V8 engine and I need to remove the exhaust manifold Bolts from the pipe to the end of the manifold but they are really rusty what is a good way to remove the bolts without breaking them off into the manifold flange

Use an air grinder or dremal tool and carefully cut the nuts from the studs. Take your time so you don't damage the threads on the stud. You could also try heating the nuts with a torch and see if they break loose

 

[paul.m]

If you have access to a torch heat until dull red glow on entire nut then use air gun [ if possible ] and 6 point socket ! Fly right off !

 

[Streetbu]

Heat the manifold where the stud screws in. Then unscrew the studs. Really the only way, or at least the quickest, easiest way.

 

[fleming442]

Prepare for the worst, hope for the best. I haven't had to do it on a G, but usually, once the y-pipe is out of the way, there's enough room to drill if necessary.

 

[69hurstolds]

It's the part you don't see is the real concern. I've seen where the stud/nut is crusty but not horrible, only to PB Blaster the nut and twist it right off because the part behind the flange has corroded away to toothpick size.

Whatever you replace it with, whether a bolt or new nut or whatever, make sure to use plenty of anti-seize. You can use GM's stuff for O2 sensors GM p/n 5613695 (superseded to 12377953 , currently p/n 88862477) which is, no bones about it as it states that it's Bostik NSBT-8N Never-Seez Pure Nickel Special. So you can save a few bucks by buying the Bostik directly from another vendor.

Or you can try Loctite LB 771. Costs about twice more, but you get 16 oz. vs 8. Unless you do a lot of lubing, I'd go with the Bostik. Probably the same formula. Who knows.

 

[69hurstolds]

I did find the Loctite 235028 (LB 771) in the 8 oz size as well. Around 22 bucks.

Info if you need it.

 

[TURNA]

alka seltzer is a anti seize as well

 

[Pronto-]

If nut it that rusted on there is a good chance the stud itself if rusted too and will need to be replaced. Be prepared to pull the manifold. Bring it to a machine shop and have them remove the stud or what's left of it. Get new studs and like above use high heat anti seize.