Broken caliper bolt

[KRAM36]

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.

[Topless]

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!

[Bruce Wayne]

Originally Posted by KRAM36

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.

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!

[KRAM36]

Originally Posted by Bruce Wayne

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.

Roger that, full set will be ordered.

Thanks for the info!

[tommy583]

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.

[Timco]

Originally Posted by tommy583

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.

Luck!!!!!!!!

[bwillia080261]

I did the brakes on my 01S not too long ago. The car had come from back east and all four top Caliper bolts had buggered threads on the very end. And all four came out very slowly and with great difficultly. I had to then chase the threads, put some anti seize on them and re-install. Not sure why this happens to the top bolts. The bottom bolts all around were fine. The fronts were particularly bad and I had to go back and forth, back and forth all the way out and was convinced they were going to break any second. What an incredible pain in the A## that was.

[Topless]

Originally Posted by bwillia080261

I did the brakes on my 01S not too long ago. The car had come from back east and all four top Caliper bolts had buggered threads on the very end. And all four came out very slowly and with great difficultly. I had to then chase the threads, put some anti seize on them and re-install. Not sure why this happens to the top bolts. The bottom bolts all around were fine. The fronts were particularly bad and I had to go back and forth, back and forth all the way out and was convinced they were going to break any second. What an incredible pain in the A## that was.

Yep, the top bolts terminate into a little well that has no drainage. It captures moisture and road salt over time which works into the threads causing galvanic corrosion. A small drain hole or simply filling the well with silicone after installation might help solve this. The bottom bolts gravity drain so not nearly such a problem. I always use a high temp thread lube on caliper bolts to help with removal next time.

[Bruce Wayne]

Originally Posted by tommy583

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.

Good Luck

[tommy583]

Well it's still stuck in there. Should i put the nuts towards the hub or on the end of the bolt?