Broken caliper bolt
 

Well I was all set to change my brakes today. New pads, rotors, hardware and caliper bolts. It stared off good. Screws in the rotors came right out. Took off the pad sensors easy enough. Pin and clip out. Squeezed on pads and they came right out. Lower caliper bolt broke free no problem. Upper caliper bolt head broke right off. :mad:
I was able to get the caliper off of the bolt by tapping on it with a rubber mallet. I've been spraying PB blaster on it for a couple hours. The whole bolt minus the head is still in the hub. So I have about 3 inches to grab onto. So far I have tried vise grips, no luck. Also tried a pipe wrench, no dice. What would be my next move? Give the PB blaster more time? Heat? Help :eek:

Get some Kroil, and let it sit. It is the best penetrating oil you can buy. You may be able to use a stud extractor with a wobble extension and a large breaker bar. MAKE SURE the car is well supported on jack stands and blocked off.

Wouldn't it be easiest to just cut it off flush and drill it?

Heat would be the next step.

+1

I agree

Show a picture of the situation at hand

This is the bolt as it sits now.http://986forum.com/forums/uploads01/bolt1430014350.jpg

I have had very good luck with a HF Micro Torch that runs on butane in situations like this. Allows pinpoint heat in tight spaces. I would definitely try Kroil if you can get your hands on some.

Can you thread two nuts on it, jam them together, and the get on the bottom one and pull like #$%&?

I could most likely still thread some nuts on to it. I didn't mess the threads up too bad. I have a small map gas torch i could use. I was hoping the pb blaster would help after letting it soak overnight.

At this point i put the old rotor back on, wheel back on and it's sitting in the driveway until tomorrow. Thanks for all the tips so far.

yeah get a couple of nuts on there. if you need to run a die on the threads to get it cleaned up enough to do so, do it.

+1 on that

Well i couldn't find any place local that carries Kroil, so i soaked it with PB blaster. I will let it soak over night and start fresh in the morning. It seems really stuck in there. So with the two bolt system should i still use some heat as well? This was really the last thing i figured i needed to worry about. I was sure the rotor screws were going to give me the most trouble. Well maybe they will on the next three :barf:

+2 on heat and use the longest breaker bar you can come up with.

Get it as hot as you can - the remaining portion of the caliper bolt will start to glow red. I used a regular propane torch and you can get it hot enough with a little patience.

For a breaker bar, I use a 4-ft piece of 1" diameter Schedule K copper pipe with a 1/2" Craftsman 18" breaker bar slid into the end of the pipe.

Then crank on that beetch.

This is how I removed the exhaust bolts on my wife's BMW that broke off in a similar manner to your caliper bolts.

Heat, heat, heat (AND the PB soak).

Try heat on the bolt and/or the hub. If you use the 2 nut method, you need to turn the inside nut to try to loosen the bolt, of course. This will cause it to back against the outside nut and hold firm. I would go with vise grips rather than double nuts, but that will definitely bugger the threads and make the 2 nut method more difficult if you have to resort to that.

Last ditch would be to cut and drill out. I'm sure some PB, heat and vise grips (or double nut/breaker bar) will do it, though. I've always had the best luck with this method.

Ready this thread does not make me happy. Will be doing pad and rotor change here pretty soon. Guess I better order some caliper bolts too.

My method, which usually but not always works :)

Soak the bolt in penetrating oil for 24 hrs. Fill the cavity behind the bolt and gravity works. Tap on the bolt pretty hard with a hammer on a regular basis to loosen and allow penetrating oil to work. On day two, tap hard again and get a firm grip with vise grips. Start by turning it in the last direction it moved (clockwise) to break it free, and then spin it out counter clockwise. Often this will work without heat. If no-go, apply heat to the bolt with map gas torch and get her real hot. Often you will hear a ping when the bolt frees. Tap again with a hammer and back out with vise grips. If the penetrating oil works you will save the hub threads. Too much muscle too soon and the soft aluminum hub threads will strip out.

Good luck!

Sorry to read about the issue, but if another bolt breaks please let us know, so I can base how many I might need.

Thanks!:cheers:

Definately. Get a full set !!The older design bolts were hex heads, which of course can round out, the newer version is a large torx head.

What i find the best way of doing these is use a long breaker bar (2ft) pull it around so you have the tension wound up tight then 'snap' it around with the wrist to break it loose.

With the OP.. i'd try the two bolt method first, and get some heat on it before hand..

get heat on it then spray release oil on it, the heat helps the oil work down the thread, then get it hot again and try and work it out again with an extender on the spanner or socket. you may find it easier to work the both thread further in, before trying to turn it out.. Though if it's tight enough to break the head off without shifting you may be in for a fight with this bolt !!

What i have found with these bolts is that it is not the top of the head (shoulder) where they corrode up, it is the tip, so it will be the last half an inch as that is open and where moisture sets and causes the lovely steel/aluminium process that we all love (not).

Get the release oil on the end of the thread from underneath.

And if all fails.. dont be scared to take the hub carrier out and take it to an engineering place for them to get the bun guns on it.

All you'll have to do to get the hub carrier out is separate the ball joint, the track arm (if the ball joint on there is unlikely to shift (mine was ******************** - but was replacing the track rod ends anyway) and undo the bolt for the drop link bolt and tap that through (be prepared for more steel/alloy corrosion here (!) and tap the hub carrier down with a rubber mallet) i just did all this on mine as i stripped and repainted the struts as the surface corrosion was about to set in.

When you put the bolts back in, copper grease the bolts so they are not such a pain next time around!

Roger that, full set will be ordered.

Thanks for the info! :cheers:

Well I'm ready to go back at it. I'm first going to run to the hardware store for some nuts (for the 2 nut method). I filled up the hole in the back of the bolt with PB blaster around 5pm so by the time i get the wheel back off it will be around 18 hours. I'll see if there is any progress before i go with heat. I'll report back, wish me luck.