Stuck bolt
 

While removing the rear brakes, the top 10mm bolt locked up halfway out. The bottom came out nice. Waiting for penetrating oil but its tight.http://986forum.com/forums/uploads02...1576180504.jpg

Your rotor indexing screw is missing.

I've been known to use alternating heat (torch) and then cold (dry ice) to "un-stick" stubborn bolts.

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For years My wife was correct. I had a loose screw.

Cover the thread in a candle wax then screw it in back in then back out keep applying the wax hopefully slowly slowly it will come out.

Seems like a good idea. I suppose you apply heat to the surrounding metal, and the ice to just the bolt? Or not?

Another (possibly dumb) question: where do you get a small amount of dry ice?

I wish you luck. I had a front caliper bold break on me. I ended up having to get a new\used hub from Woody. The best penetrating oil I found is called Kroil. I think you can find it at Napa.

Mix acetone and ATF half and half.
Shake hell out of it each time you use it.
Seal it up when on the shelf as the acetone evaporates rapidly.
Works better then anything I have ever used.

I've never used dry ice to get stuck bolts out, but I have used a torch. Just get the bolt and the hub right around the bolt hot and see if that does it. Blue99's idea of using wax on the threads is interesting, I've never heard of that. Maybe you can find a money scented candle for the wax, the car will probably like that scent the best.

If you get it out successfully, make sure to chase the threads in the hub with a tap, and use a new bolt.

Good luck!

I have had success with drilling out the center with ever increasing sizes. Try to get all the way through the bottom. When you get to +/- 0.312", lube it up again and try a screw extractor. A couple of heating and quenching cycles will also help. Just don't get carried away with the heat. Give the lube time to work, patience will be rewarded.

I tried heat first, Carful not to cook any brake fluid/lines in the process. No luck. Going for the acetone concoction next. Thanks for the imput.

you say it came part way out then locked up.????
I wonder if it is cross threaded?
If you can turn it in- try working it in and out with the acetone -ATF concoction I mentioned. When you use it let set for half hour or so after you put it on the bolt before you try to get it out.

It's odd that it gets stuck halfway out. Have you tried bolting the bottom bolt back in? Having the bottom bolt in maintains the caliper alignment and relieves lateral pressure on the stuck bolt.

It did create a gap behind the caliper before it bound so I poured the special sauce as close to the base of the bolt that I could. It didn’t feel crossed, more of a galled feeling.

I don't know how much play there is between the bolt and the thru-hole on the caliper, but what you're describing seems to me like the bolt is binding up on the caliper itself, not the threaded parts. Try running the bottom bolt back in and snug it up. This will help keep the caliper down while you're working the other bolt out.

The caliper will slide ( a little) on the bolt shaft. I have about 3/4 in. of thread still in the hub. The bolt I got out looks to have been coated in something. The threadd are not clean but it came out nice.

Unfortunately, I think the damage is done. From what I've experienced, if the bolt starts coming out and then gets jammed up. Part of the aluminum threads have stripped and are attached to the bolt. As the bolt is coming out, those stripped threads are now binding against good threads. I hope I'm wrong

That's what I thought until I put a magnet on it and it stuck. They both look the same. I was wondering if low and slow torque or high impact would lessen the chances of it breaking.

Ah yes, that's aluminum. I forgot about that. Aluminum and steel don't like each other. There is bad chemistry between them.

Likely you're screwed. Snap it off, drill it out, timesert it. Good as new.

Forgot the picture http://986forum.com/forums/uploads02...1576244078.jpg

Whats the thing between the magnet and the bolt?

The Caliper Bolts are 1 time use. As Woody says most likely the Al threads are stripping and galling causing your problem.
I went to Tarret Caliper Studs so I don't have this problem again.

It's just a magnetic wandhttp://986forum.com/forums/uploads02...1576245852.jpg

oh.

yeah, so the aluminum threads of the knuckle are likely stripped binding the steel bolt.

I waited until 6:00 a.m. when it was in the low thirties to heat the knuckle and try again. success! Thanks for all the helphttp://986forum.com/forums/uploads02...1576249443.jpg

Yay! You are lucky.

Yeah, persistence sometimes pays off.
And maybe patience too? Sometimes I think it takes a while for the Liquid Wrench or homemade "Sauce" or whatever to work its way down the threads. Don't have a ton of experience with these, but I'll usually spray some on there, typically followed by a few light taps of a hammer to help loosen things and help the stuff penetrate. Maybe an hour later I'll repeat. Then, if no luck, do it one more time at night and let it sink in over night. Have had some success with it..

there looks to be some schmoo in the threads of that one bolt, so make sure your knuckle threads are still ok.

You going to use some anti-seize upon reassembly ?

I know you really meant that as a statement not a question ;)

Damn I didn't even think of the caliper being aluminum.
Explains the issue.
good to see you got it out

The bolt threads into the upright or knuckle as some people call it. The holes in the caliper are non-threaded through holes

I use a thin coat of anti-seize on my original caliper bolts, they're only 20 years old.

Thanks for the clarification.
Am I correct in assuming the upright is aluminum????
My thought is that at some point in time that bolt was over tightened.
That tends to draw the threads out of the aluminum. Thus the aluminum material in the bolt threads. Also I like to use anti-seaze on anything threaded into aluminum.

Yes the upright and caliper are aluminum but the bolt is steel. I believe it's a corrosion issue as I see it happen on cars that either spent most of their life in snowy conditions or very close to the ocean. The exhaust manifold bolts have a high rate of corrosion issues too..

I got my new bolts today, just waiting on the m12-1.5 tap to clean up the threads.

Tapped, flushed and torqued. Back on the road. After 17 year, there does show signs of the two different alloys fighting each other.
http://986forum.com/forums/uploads02...1576745018.jpg

Hopefully you used anti seize so this won't happen again............

Yes we did. However, 5 minutes down the road one of the ebrake retainer springs went and shut me down. Where do you find those little gems? Are the boxster s ebrake parts the same as 2.5, 2.7?http://986forum.com/forums/uploads02...1576755069.jpg