Ok so removing the stock cat...
 

I recently got ART testpipe and I was really excited to see the difference until the shop encountered a problem.

There are 3 bolts on each sides that connects the test pipe from the header. They were able to remove 4 bolts out of 6 but they couldn't remove the last 2. They used chemicals, heavy duty gun, etc.

Any tips on removing them?

The shop said it's 'naturally' welded due to heat+cold weather:shakes head:

The only alternative I have is to get the header out, and somehow cut the welded part...

Any thoughts or tips are much appreciated !

Those bolts are called Demon bolts by many people on the forum. A quick search for "demon bolt" might point you in the right direction.

As for myself, I used a long breaker bar and got one off clean, the other snapped off. Keep soaking the bolts and make sure you're on the nut all the way with a 6 point socket, you'll get it eventually.

Mine took forever, they were a complete PITA

you can heat the PITA bolts and that will make it so the bolt contracts and you will be able to unscrew it. Most body shops will have a torch or something, that is how mine was able to install them.

I just had my HFC's replaced and if I remember correctly they broke 2 bolts trying to get them out.

:iagree:

Demon Bolts Strike Again! :ugh2:




Moved to right section

Bolts are accessed from under the hood btw using lots of extensions. I don't understand why any reputable shop isn't prepared to deal with a stuck bolt, they shouldn't just be giving up.

You should also wait until the car cools down. Metals tend to expand when hot. It may be easier to take off after it cools.

this^^^

I did it on my own so this shop needs to get back in there. breaker bar, from what I remember, 12"/6"/3-6" extention and a pipe for leverage. I cant remember if i used a swivelle socket or not......

Yes a swivel will be needed unless you want to completely remove the intakes in which case you might not need one.

^ got it I will print some of the posts and bring it back to the shop. Hopefully they will get some sorts of idea.

The shop didn't risk breaking the bolts; yet almost all my buddy with 370z broke theirs.

This is a common problem on not only the 370, but on quite a few different cars with cat/downpipe bolts/studs.

I've personally had good luck on other cars with an acetylene torch to heat the bolts and studs up before messing with them. Another option is to soak them in PB Blaster for a bit.

I used a nice impact gun with some 1/2" ext and a 6pt impact socket to rip them off. Don't even try them with a 12pt not worth the risk of rounding them... Because that's when life will get difficult

I guess removing mine w/o breaking them must make me a boss.

Anyway, I know it was mentioned already, but a shop giving up on a stuck bolt is worrisome at best...

the 1/2" extensions are key. the 3/8" flex which makes the process difficult and dangerous. learned the hard way here.

My "demon" bolt.

http://hotimg23.fotki.com/a/63_239/6...MG_0648-vi.jpg

And my FrankenTool.

http://hotimg23.fotki.com/a/63_239/6...0644-vi383.jpg

:tup: back at ya

Mine weren't too bad. I used a 1/2" ratchet and extension with a piece of pipe that I slide over the ratchet for leverage

If the bolts break....then there is no choice but to remove the header and work from there is it?

What do you mean if the bolts break ?, cant you just hammer out the stud if you break the bolt ?

I haven't done it, but why can't you drill the stupid things out?

Find a EXTRA LARGE 1/2" breaker bar (like used for tightening lug nuts) and use a 3 foot long 1/2" extension and connect it to a 1/2' impact socket (14mm).

Use only 1/2" socket tools and get ready for some serious torque!!!

PB Blast it, put on leather gloves, one hand on the bar pivot point, the other hand at the far end of the breaker bar. Brace yourself with a low/stable stance and crank that bitch until the bolt yields or snaps off. BAM!... Problem solved.

Unfortunately there is no way around it. That's why its called Demon Bolt.

This sounds exactly like how a proper man would handle the demon bolts! The only things I can add is that you may want to let some PB Blaster soak for a while and a pipe fitted to the end of the breaker bar will give you more leverage if you need it.

I didnt use PB Blaster, but otherwise that was my exact setup. Having a one-piece massive extension was nice. That, and a big breaker bar plus a nice pipe to double its length, and it STILL required some serious torque. But once it broke, it was easy obviously.

I'm printing this and taking it to the shop.:driving: Do you mind? :happydance:

Wow!


I'm sure many of the DIYers have all said this after spending unwanted time on bolts!

"Wish I had a gun for this bolt"

I know I did when it took several hours frustrating over my bolts! The noise of a bolt breaking free is however a beautiful noise!

LOL!:happydance: Go right ahead.

We are having a Black Friday sale on everything tomorrow.:tup:
Type in the discount code "Black Friday" and we will apply free mainland shipping when it is processed.

OP, any updates on your demon bolts?

I will be tackling this install this weekend. Wish me luck!

nice job

How were you guys able to get to the bolt on the driver side? There is a bar obstructing the bolt so my wrench can not lock onto the bolt?

http://i109.photobucket.com/albums/n...2/1ec0152e.jpg

I used a universal joint on that bolt at the end of all the extensions...had some help from under the car to get it on the bolt head right...good luck

How did you avoid that bar?

It should be a straight shot. My extensions laid up against the steering rod but not to where it bounded it in any way. It's ok if there's a little pressure on it. If you feel it's to much then yes use a swivel. But best if it's a impact socket.

Okay. I was scared to move that bar.

Dont worry about the pressure on the steering bar. It'll be hard if not impossible for u to break it by just pushing against it. USE AN IMPACT SOCKET. I learned that the hard way when i was doing mine, Impact socket got it off after a couple seconds of putting my full body weight on the breaker bar.

Helped a friend of mine removing his cats last weekend. We were able to get everything off except the two demon bolts. We spent about 5 hours trying to get those stupid bolts out. We ended the day with the two bolts still in place, with the passenger side stripped. We managed to break a universal as well. Friday my friend and another one of his friends went to work on those two bolts again. They used a bolt puller and actually managed to break one of them before getting them off. They used an Acetylene torch to heat the bolts then tried again. This time the bolts snapped and they were able to get the cats off.

Not sure if this was suggested yet or not, but i know from experience that if you spray some penetrating oil on it then start your car and heat it up for a little bit, wait for it to get cold and do that a few times its MUCH easier to get off. Acts like a normal bolt after that...

Thats what I did to avoid the bar.

My demon bolt besting apparatus was arranged like this:

1. impact socket (6-point of course)
2. then a 1/2 inch universal joint (to help get around the steering rod)
3. a 1 foot long 1/2 inch drive extension
4. another 1/2 in drive U joint (had two so I figured why not)
5. a 2 foot long 1/2 in drive extension
6. finally a 1/2 in drive breaker bar

I had soaked the bolts in Kroil the day before which helped I'm sure.

Demon bolts 0 - IDZRVIT 2!!! I just came up from my garage after spending 2 hours getting those two bastirds out. I put PB blaster on the right side bolt - waste of time as the oil can't penetrate. How do I know? There was no penetrating oil on the threads when I removed it. I used a 1/2" drive 6 pt impact socket attached to a 6" extension attached to a universal attached to couple of other extensions. Put a 24" pipe over the 1/2" bar and applied torque. Success. The left side was the same method without the universal and I removed the air box. Sheared the head of the bolt clean off. Success. The key to get those bolts out is to make 100% sure that the socket is square onto the bolt head. If not, you'll round the head of the bolt. There isn't any trick to get these out such as using heat and penetrating oil and ??? Quality tools and a strong forearm is all that is required.