caliper mounting bolt siezed in brake caliper=stripped threads in caliper!!! BREMBO's

[gills]

Basically what the title says. I guess since i've been tracking the car a decent amount with race pads the bolt was fried in there. I knew something was wrong as soon as i started to loosen the top bolt. I thought the bolt was going to break but since the caliper is made of aluminum the threads in the caliper gave instead. The bolt is fine but just has some aluminum stuck in the threads.

Has this happened to anyone else and if so what did you do?

The last thing i want to do is buy a new caliper.

I'm thinking i can go to a machine shop and have them clean it up and re-thread it to a bigger size bolt. Or have them weld the hole up, redrill and thread to the stock size bolt.

Any ideas please. I have a track day next thursday Nov. 10th!!

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[re92]

Exact same thing happened to me. I took it to the mechanic - two of the bolt heads broke in one caliper, and on the other side, the bolts destroyed the caliper threads when they came out.

I ended up buying a used set of Brembos and put some anti-seize on the bolts before installing it.

Raj

[Draken]

i'm waiting for Awesome to post. This exact thing happened on his STi about a month ago. same situation, car that was tracked a bit, threads in caliper stripped out. I passed the link to him.

Chris H.

edit: raj beat me to it

[re92]

BTW, those bolts are tough mofos. Good luck getting them out if they snap inside the caliper.

Raj

[gills]

Originally Posted by re92

BTW, those bolts are tough mofos. Good luck getting them out if they snap inside the caliper.

Raj

*****! I just took the other side off with no problem and put a good amount of anti-seize on the threads. The last thing i want to do is buy a new/used caliper. There has to be a cheaper solution.

Thanks for the input though guys.

Oh and what's the torque on the bolts anyway?

[jamesfacts]

Tap kit?

[eric94501]

Do you guys wait for the caliper/brake to cool down before you unbolt the calipers/brake?

[gills]

Originally Posted by eric94501

Do you guys wait for the caliper/brake to cool down before you unbolt the calipers/brake?

My brakes were cold when i started working on them. I just rolled her out of the garage and started working.

Anyone else strip their caliper threads??

[04SilverSTi]

the same bs happened to me last summer, ended up waiting 2 weeks to get a new caliper from brembo and $800 later, i was pissed

[gills]

Originally Posted by 04SilverSTi

the same bs happened to me last summer, ended up waiting 2 weeks to get a new caliper from brembo and $800 later, i was pissed

Wow. you see, that's just unacceptable for me. There's no way in hell that i will pay for a brand new caliper especially at that price. There has to be a cheaper solution and i'm on a mission to find out what it is. I'll be contacting a few machine shops by me tomorrow to see what can be done.

[re92]

Originally Posted by gills

Oh and what's the torque on the bolts anyway?

114.3 ft-lb. Here's a diagram: clicky clicky

Let us know what you find out You could try Helicoiling it.

Raj

[burnera]

the bolts are coarse thread right? if so then wow, weak --- aluminum batman.

assuming they get the bolt out the only ideal (and trackable) solution would probably go up a size in bolts, basicly rethread the caliper with a larger tap, then you'd have to drill out the mounting hole too.

the machine shops may have a better solution, but MAN that sucks!

[gills]

Originally Posted by burnera

the bolts are coarse thread right? if so then wow, weak --- aluminum batman.

assuming they get the bolt out the only ideal (and trackable) solution would probably go up a size in bolts, basicly rethread the caliper with a larger tap, then you'd have to drill out the mounting hole too.

the machine shops may have a better solution, but MAN that sucks!

The bolt is out and is in perfect shape besides aluminum caked in between the threads that were once threads in my caliper

What you said is one solution but not on the top of my list. I'll keep you guys updated. And yes it does SUCK

[PARANOID56]

you might be able to use a retap, were you drill out the hole, and retap it, then put the insert in. this will give you back the stock size thread and size. Not sure this is the best way to fix this, but it would be the cheapest.
also, you could take it in and have the hole retapped. and just use a larger size bolt.
either way, that really sucks. i guess the dissimular metals, just didnt work out to well. and the metal botl gauled up the alu too much.
Shane

[Jasper]

heh, you want a permanent fix? find yourself a stainless steel helicoil.

(stainless steel and aluminum, apparently because of differences in the chemical compounds of the metal?, love to freeze together to the point where you'll NEVER get them apart. then, just use a mildsteel bolt (Grade8 or better of course), and it *should* never freeze again.


aluminum is funny stuff, and once something corrodes in it, its done. you'll never get it out in one piece



drilling it and retapping a larger hole is an option, but a pain in the ass....cause then you'll ALWAYS have one out of 8 of your caliper bracket bolts be a different size. the helicoil would allow you to keep the stock sized bolt.




i dont think NeverSieze is a good idea. stuff like that tends to make bolts a little more likely to back themselves out a bit, which is NOT a good thing when it comes to brakes. instead, i say just clean them up with a wirebrush, and reinstall them. (plus, if the helicoil works well, you can just repeat the process if this happens again **unlikely, but possible**

[gills]

Originally Posted by JasperSTi

heh, you want a permanent fix? find yourself a stainless steel helicoil.

(stainless steel and aluminum, apparently because of differences in the chemical compounds of the metal?, love to freeze together to the point where you'll NEVER get them apart. then, just use a mildsteel bolt (Grade8 or better of course), and it *should* never freeze again.


aluminum is funny stuff, and once something corrodes in it, its done. you'll never get it out in one piece



drilling it and retapping a larger hole is an option, but a pain in the ass....cause then you'll ALWAYS have one out of 8 of your caliper bracket bolts be a different size. the helicoil would allow you to keep the stock sized bolt.




i dont think NeverSieze is a good idea. stuff like that tends to make bolts a little more likely to back themselves out a bit, which is NOT a good thing when it comes to brakes. instead, i say just clean them up with a wirebrush, and reinstall them. (plus, if the helicoil works well, you can just repeat the process if this happens again **unlikely, but possible**

interesting. Are all helicoils stainless steel? The stock bolt is a nice beefy grade 10 bolt that i would like to reuse.

As for the antiseize, i don't think it's a problem. If anything it's a good thing to use for these bolts because it's highly recommended to use antiseize with aluminum due to it's relatively soft nature. Also, there are lock washers on these bolts and they're torqued to over 100 ft/lbs. I don't think they're going anywhere.

[Draken]

galvanic corrosion is what you speak of. Just like how stainless spring perches will nicely corode themselves onto aluminum threaded coil-overs.

Basically, you will drill out the caliper to a larger size, then rethread to the od of the helicoil. The stock bolt will now thread into the id of the helicil. I would personally use anti-sieze on these bolts. In fact, I might do it this weekend, because i dont want to run into this problem down the road, after another year of track days.

Chris H.

[gills]

Originally Posted by Draken

galvanic corrosion is what you speak of. Just like how stainless spring perches will nicely corode themselves onto aluminum threaded coil-overs.

Basically, you will drill out the caliper to a larger size, then rethread to the od of the helicoil. The stock bolt will now thread into the id of the helicil. I would personally use anti-sieze on these bolts. In fact, I might do it this weekend, because i dont want to run into this problem down the road, after another year of track days.

Chris H.

Time to do some measuring to see what size helicoil i'll need.

[thesmokingman]

I used a helicoil when one of my a-arm to chassis bolts stripped. Go here:

http://www.mcmaster.com/

[Uncle Scotty]

...gentlemen.....just make sure that any anti-seize that you use with aluminum contains NO graphite....graphite and aluminum is BAD juju.

[gills]

Ok,

ordered a helicoil thread repair kit.

Size of the bolt for anyone in the future with the same problem:

M12x1.50 fine thread

I'll be receiving it tomorrow morning and will be attempting to install shortly after. I will keep everyone posted.

Tom

[gills]

Install was a success. The whole process is exactly like making a fresh thread on a drilled hole except for the last part which is installing the helicoil insert. Just had to take my time drilling to make sure everything was as straight as possible.

I haven't driven and tested her yet because i am waiting on some other parts to install(JDM STi coilovers, RCE Camber plates ) while i have the car up on stands. But everything seems to be lined up perfectly and i was able to torque to spec. which seems way high IMO for an aluminum caliper(114.3ft/lbs).

I was able to clean the aluminum out the threads of the suspect bolt by cutting a properly sized nut in 1/2, putting it below the caked threads then loosening it off. Worked really well.

so far a big thumbs up to helicoil inserts for using the same sized bolt in the STi Brembo caliper.

Total spent: $70.00

[Jasper]

Originally Posted by gills

Install was a success. The whole process is exactly like making a fresh thread on a drilled hole except for the last part which is installing the helicoil insert. Just had to take my time drilling to make sure everything was as straight as possible.

I haven't driven and tested her yet because i am waiting on some other parts to install(JDM STi coilovers, RCE Camber plates ) while i have the car up on stands. But everything seems to be lined up perfectly and i was able to torque to spec. which seems way high IMO for an aluminum caliper(114.3ft/lbs).

I was able to clean the aluminum out the threads of the suspect bolt by cutting a properly sized nut in 1/2, putting it below the caked threads then loosening it off. Worked really well.

so far a big thumbs up to helicoil inserts for using the same sized bolt in the STi Brembo caliper.

Total spent: $70.00

glad we could help

[re92]

Sweet dude. Thanks for the write up.

Raj

[kursplat]

i dont think NeverSieze is a good idea. stuff like that tends to make bolts a little more likely to back themselves out a bit,

if your worried you could always drill 'em for safety wire while they're out