So I got a disc posi rear from an 81 Trans Am to put on my 50 Chevy. I go and begin breaking it down so I can replace the rotors *one was rusted on like a murf* and find that the last person who owned it didn't have all 4 bolts that go with the calipers, so on one side, they subs***uted a real hex head bolt. That thing was so damn rusted that I had to cut the head off to remove the caliper. Because of the structure of the caliper, there was no good way to get a wrench on the thin head (about half the thickness of any hex head bolt that I've seen) and it's rusted solid. So now I have the shaft of the bolt still firmly embedded in the backing plate and it won't budge one bit. I've tried PBlaster, propane torch, and even the propane torch/wax combo...IT AIN'T MOVIN! There's not a lot of clearance to get a pair of vice grips in there, but I did flatten the threads on each side so I could get a better grip on it....but no luck with that, either. I've considered the posibility of having to try and drill it out and probably re-tap the hole, but other than that, I'm at a loss. Any other ideas??
Is the caliper nice? replace? If you drill your pilot hole center, then use the extractor or drill a size or two smaller you could end up with just the threads sitting in there, you could pick out. may not have to tap it? I think you should save yourself some aggravation and get another one, you'll end up screwing with that thing a day or two till its f'ed up and you have to get another one any way so save your self getting pissed off and you'll know its safe. If you tap it you'll have to make the other holes bigger to won't you, will pads fit if you have to do that.?
Yep, get a real torch and once it's nice and hot it will come right out. The only good use for a propane torch is to do plumbing work.
Yeah, but the backing plate is a one part deal that won't fit over the hub. It went on the axle when it was mounted to the pumpkin, I believe....TOO much trouble for that. If they make 2 piece replacement plates that will fit that rear, I might consider that option. Up next is the extractor kit, I reckon. I.....hate.....rust.
heat only the part the bolt is screwed into. that way it expands away from the bolt so you can get it out, heating the bolt will only soften it and it will twist off. can you see the back side of the bolt or is it a blind hole? If its a blind hole you can drill a small hole and spray PB into it to help from the back side. If its not take your time and heat the bracket. OH and North Jersey is a bad place to live if you hate rust!
Cool, I think my neighbor has a legit torch I can use....thanks for the advice on heating the bracket. The head is shaved off flush, and the shaft of the bolt is sticking out of the other side about 2 inches. I've got the whole thing soaking in PB overnight, so we'll see what good that does sometime tomorrow. North Jersey is just trouble in general, not *just* with rust! It's not even this bad north of Memphis, where I'm from! I don't ever remember seeing something rust overnight before I moved here.
If you can weld a nut on the part of the bolt thats left ,after it cools sometimes they screw right out,give it a try
a real torch, get it nice and hot and then try to wiggle the bolt back and forth, dont just try turning it out it would most likely just twist off, back and forth a little further each time, slow and easy, two days ago i removed a broken exhaust maniflod bolt that was snaped off flush, my method is to take a 1/8" x 1" piece of flat bar about 8" long and drill a hole in the end the size of the bolt, then i plug weld it on, now i have a handle to work with, go slow.
Try a 50/50 mix of auto ****** fluid and acetone, I got the idea off of a thread on here and it work like a charm on a bolt that nothing else would touch. I mixed it up and put into an old oil can I had and just soaked the bolt over night, next morning came right out. Worked better then the kroil I usually use.
The backing plate unbolts but the axle has to come out. I am very familiar with these as I put them into 1968 Firebirds with a few mods.
If it's that rusty a look inside wouldn't hurt. Then you could pull the axle and take the whole works off as far as the bracket goes. Could be if it's the wrong bolt, it has the wrong threads too.
I've used heat and dry ice. Heat the bracket and ice the bolt. Heat makes the hole expand and ice makes the bolt constrict. If you have the clearance wire brush the exposed threads of the bolt as good as you can. I have used the other methods mentioned in this thread. The one you use depends on the situation and the room you have. If the part can be removed then by all means I would remove the bracket to have unrestricted access to the work at hand.
I planned on cracking open the pumpkin, but I'm in hopes that everything is in working order. It turns freely, and it appears that only that side really got moisture, as the rest of it only has some surface rust. Oddly enough, the bolt was incorrect in type, but correct in thread....so whoever did it only half screwed me over I'm going to attempt several things today, so we'll see what works....hopefully soaking overnight in PB did some good.
I dont miss the rust belt at all! A real acelatine torch should do it. There are also bolt extractors that look like a socket but have teeth. Used them to get the rusted in half body bolts out of my cutl***. Cant remember thier exact name but worked like a charm.
Another old method I've heard, but never used, is to heat the area with a torch and hold a wax candle to the bolt. Supposedly the heat wicks the wax into the thread area helping to free the bolt, much the same as soldering a copper pipe joint. FWIW
Did the candle wax and HEAT bit to get the purch bolts out of an old axle. Been in since 1948. Worked great.
I can burn a broken or rusted out bolt with a torch and not damage the hole or existing threads. it takes alot of practice and a steady hand, but worth it when it comes to things like these. its damn near impossible to explain with words, its something you just gotta see diego
It sure is...Once as I was turning out the last broke off exhaust flange stud with my easy out, the easy out snaped. A torch and 2hrs later after burning/drilling and re tapping I was done. Since your axle is out of the vehicle, I would cut the bolt off flush, and drill it out and re-tap it. It may save some grief
heres a couple of pics of my last extractor, a hole drilled at the end and plug welded to the stud snapped off flush, i had to bend an offset in the end for clearance, the whole thing is 8" long.
That's what I'm doing now. The extractor wouldn't fit because of the clearance between the stud and the backing plate/flange. That's 50 bucks back in my pocket when I return it tomorrow! I drilled it thru and am slowly increasing the diameters of my bits until I get close to the threads, then tap it. One stinkin bolt has turned an otherwise easy job into a little slice of fubar.
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