Rusted Exhaust bolts

[Fred Mc]

I know this isn't a question specifically on buses but its close.
I'm trying to replace a gasket from the exhaust manifold to the exhause pipe on my chev 1 ton truck with 454 engine. Of course the bolts are rusted and to make matters worse they are studs coming out of the exhaust manifold rather than bolts which means I don't want to damage them(or destroy them. Ive soaked them in Liquid wrench but they don't want to move and I know if I force them they will probably snap off. Anyone have a suggestion on how to remove these frozen nuts.

Thanks

Fred Mc. GM PD 4106

[JackConrad]

Try carefully heating the nuts with a torch, then while they are red hot, use an impact wrench with a 6 point socket. Jack

[ChuckMC8]

Fred, when I worked in the muffler shop, this proceedure was a daily occurence........As  Jack said, use a torch and heat the nut to "glowing" red.....then quickly put the socket on it and back it off......if it starts making a squeaking sound as you're turning it, stop and heat it back up.
    This is much easier done on a lift rack. IIRC, it was about $30 a side to replace donuts in BB chevys.
HTH, Chuck

[Barn Owl]

Jack and Chuck are right, use heat. If you break a stud off weld a nut to it and you should be able to back it out. I have seen it done even if broken down in the stud hole. I would try a socket or wrench first before an impact for the reasons Chuck stated, you need to listen for the squeak.

[jjrbus]

I give up, I quit, never again !!!!! When ever I get to a nut that does not want to come off, I get out the angle grinder, the dremel a drill,I may even buy a nutcracker. I am never again brakeing a 3/4 inch braker bar, snapping a stud that is going to take hours to replace or setting something on fire. A nut costs much less than a can of liquid wrench!!!!!! Try it, you will like it.

[Sammy]

Fred, I use heat - 'ole reliable - the torch, on the nuts.
I also back 'em off by hand, so I can feel and hear them as they unscrew.
Lots of squealing, add more heat.
Sometimes if they still insist on breaking, I drill out the stud from the manifold and install a bolt with a locknut - if there's room.
Good luck. 

[Sojourner]

And you have go one size smaller 6-points socket because rusted hex nut may slip using OEM nut size socket. So check it out before torch-heat & remove.
However if it badly rusted out of shape....may have to use cut-off grinder or shock aborber"s nut-splitter or cracker...you may laugh but I have one in my tool box since 1960s. It available. http://www.northerntool.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=6970&productId=34573&R=34573&cm_ven=TL&cm_cat=ERK&cm_pla=Google&cm_ite=handtool

FWIW

Sojourn for Christ, Jerry

[Gary '79 5C]

All methods listed here will work, IF there is enough room to get access for the torch, nut buster, etc.  On a 1 Ton P/U, I would imagine there is sufficient space.
I replaced my MIL's exhaust in a 14 yr old Camry, and could only reach the nuts with a 24" extension. Only one hand could barely reach.
I used Kroil & waited 2 hrs, used Kroil & waited 4 hrs, came back next day Kroil and broke all four nuts clean. All 4 gave a yelp when releasing. I was rather tight myself until I knew the studs were still intact.

Gary

MIL actually trusts me to replace her brakes as well......

[Fred Mc]

I took the advice on this board and used heat. The nuts came off slick as a whistle. Hardly any effort at all.

I;ve been doing mechanical stuff all my life and never knew that method. You learn something new everyday.

Thanks again.

Fred Mc.