need help with frozen exhaust bolt

pokeyman

New member
I tried penetrating oil and removing the bolt when its hot but it does not want to come off. Is there any other ways to remove it without breaking the bolt. Its the bolts is connecting the cat to the exhaust manifold.
 
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I just went through this, I ended up shearing it off and drilling it out. You could try heating it up with a torch but be careful if there is any oil that has leaked into the area. If you absolutely must remove it and can’t drill it I would repeatedly heat it and use penetrating oil until you are able to remove it, but with a lot of exhaust bolts especially in areas with rust even that might not work
 
I assume you let sit over night with penetrating oil. You may need more heat too. I had to do the same thing last month, I soaked it several days in advance. The nuts are soft brass if I remember correctly so use a 6 pt socket. Or you can always split the nut and find a replacement at HD or Ace hardware since the Osh is gone near you.
 
What kind of penetrant did you use? Hopefully, PB Blaster, Liquid Wrench, or Kroil. I believe those are the top 3.

I agree with letting it set overnight. Also, tap around it with something metal - the vibration will help it wick in better.

I hope you didn't use WD-40, which is fairly worthless for anything except de-greasing or displacing water. It is a piss poor penetrant, and a fairly useless lubricant.
 
Locktite makes a freeze off spray that may work. I'm sure other companies do to. The can I have I have no idea where it came from, I don't use it often.
 
For exhaust to cat nuts and bolts/studs removal, heat em up cherry red and they will come out. I use a bottle of MAP gas. I had a broken stud I had to heat and wiggle back and forth with vise grips till I got it out. You can replace the studs with a stud kit that has brass nuts that wont seize, can get at Autozone.
 
I tried it with a torch at the house but couldn't get it. Needed an acetylene torch to finally get it glowing red. In my experience all penetrating fluid is junk. Heat is the only way to go and I work on rusty semi truck differentials all day. Only use heat over here.
 
Which bolt?

I had a fun time removing one of the bolts there as well and I have a completely Southern truck, with virtually 0 rust. Usually a day of PB Blaster gets all my bolts off easily.

With 2 of them, I was able to get enough extensions to torque around the cat, but with one (the bolt right between where the exhaust manifolds combine to go into the CAT, if I recall) I couldn't get my ratchet to fit, even with swivelers. It's just a really odd angle.

A box-end wrench fit, but I had a bare few centimeters of clearance going through the wheel well around the frame and just couldn't get enough torque that way either (not to mention that seemingly ALL box-end wrenches are 12 point and I didn't want to strip it.

I wound up having to saw-zall the cat completely out, as close to the exhaust manifold as possible, and then I was able to get that last bolt out in honestly 2 minutes with the proper extensions.


The problem as I saw it is that the factory cat has a thin piece of metal connecting the 2 pipes all the way to the base where it mounts to the exhaust manifold. That piece of metal prevents the socket from getting a good bite (until I cut the cat)
My aftermarket cat (Walker Quiet-Flow) has 2 completely separate pipes right up to the base where it mounts to the exhaust manifold; no metal connector. I was able to get a socket on it, no problem at all.

If I could find a 6-point box-end wrench, that probably would have made my job a lot easier.
 
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torch it then get a 1/4" punch and hit the bolt with the punch and hammer a few times and try to wrench it. it will take a few times, but with persistence, heat and careful punching the rust will eventually free up.
 
Also try tightening it just a little. That will sometime break some of the rust up on the threads enough to then start backing it off. All these suggestions are really great so far!
 

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