Rusted Bolts help

[sp33dracerman]

Hey guys anyone have any ideas what to do if your catalytic converter bolts are rusted on, I used anti sieze and a breaker bar and they just wont budge

 

[oneradride]

Torch, heat will usually do the trick

 

[EliteTahoe]

Torch and Tar. Best anti seize lube ever.

 

[withac]

Growing up on the farm if we had a nut we couldn't break loose we'd get a chisel and notch it into one of the flat surfaces real good, don't know why this worked, if it was just the banging or when it got the small split it helped spread the inside of the bolt therebye loosening it up. I imagine this would be difficult on a cat but if you had something to back up the opposite side of the nut so the impact went into the chisel and not the whole systems it might work.

 

[jniolon]

I've never done these... is it a bolt that's frozen ? or a nut on a bolt ? can you get to the threads ?

I've never heard of Anti-seize doing anything to help break loose a frozen nut/bolt. Anti-seize is put on at installation to prevent that..

a penetrating oil is what you need... PB Blaster sprayed liberally on the threads... wait a few minutes (15) do it again.. probably better over night. Wal mart and all auto parts stock this

http://blasterchemical.com/display.cfm?p=50003&pid=4


another is Kroil... it's like the king of nut busting but harder to find locally.
better auto parts stock this

http://www.kanolabs.com/

as mentioned above... heat Heat the nut and it will expand and break the rust seal.. try to keep the bolt cooler than the nut...I've also heated the nut and applied cold to the bolt... using a can of computer keyboard cleaner turned upside down and sprayed on the bolt threads (not the nut)

something else to try..instead of loosening... try to get it to crank just a bit tighter...breaks the rust seal

last but not least...I've seen this work before on old tractors... if you can get to the threads at the nut... clean all the loose stuff off the joint (bolt thread/nut...heat them up and drag a candle over the joint. The wax (paraffin) will seep into the thread joint and it will break free...

best advise is take your time ESPECIALLY if this is a bolt in a blind hole..snap that off and you're dealing with a whole new set of problems.. BUT maybe an opportunity to buy more tools

good luck
John

 

[Rivieraracing]

What you could also do is purchase what is called a "nut cracker", it mounts on the side of the nut with points at each end that when tightened down will actually split the nut off of the bolt, kinda drastic but for exhaust stuff is often times a better alternative from busting off a bolt. Hop on Sears website under the tools section and type in nut cracker and you will see what I am talking about.

 

[rockman20]

All the above!

If I am ever working on exhaust, I will let the vehicle sit for as long as I can. And then I just religiously soak everything in pentrating oil. If I walk by it, I spray it. If I think about it, I go out and spray it. Sometimes I have more penetrating oil all over the dang place, but it usually does the trick.

I have seen the candle wax work great. Problem is unless you have a nice hoist, this can be tricky while laying on your back trying not to drip hot wax all over yourself.

Even with the penetrating oil if I can't bust it loose, I try tightening it a bit. If I can bust it loose either way then I get the torch. Be warned.........penetrating oil burns so make sure you are aware of everything that has been hit with the stuff BEFORE you start.