[Sam!]

Hi all,

In the process of rebuilding calipers, of course one of the caliper bolt was seized. Anyone know where to source a replacement? Looking for the bolt circled in red.

[johnung]

Originally Posted by Sam!

Hi all,

In the process of rebuilding calipers, of course one of the caliper bolt was seized. Anyone know where to source a replacement? Looking for the bolt circled in red.

Contact Dave Zeckhausen at Zeckhausen Racing. He is the brake guru.

[Sam!]

Originally Posted by johnung

Contact Dave Zeckhausen at Zeckhausen Racing. He is the brake guru.

One of the first I reached out to but he's stumped as well. Reached out to Brembo as well but message will most likely be ignored. Most other places just wants me to buy a whole caliper.

[johnung]

Originally Posted by johnung

Contact Dave Zeckhausen at Zeckhausen Racing. He is the brake guru.

I just enlarged your photo. I'm pretty sure that I was told not to ever undue the bolts that hold the caliper together. Not meant to be serviced

[Logicoeur]

Originally Posted by johnung

I just enlarged your photo. I'm pretty sure that I was told not to ever undue the bolts that hold the caliper together. Not meant to be serviced

It would be impossible to powdercoat/rebuild the caliper then. There are plenty rebuild kits (even from Brembo) so I doubt it is meant to be unserviceable

[Billfitz]

Post a picture of one of the bolts you removed. It appears to be an external torx head bolt, which are rare but not impossible to find. If that's the only thing about it that's out of the ordinary you can probably substitute a bolt with the correct length and threads with a different head if you can't find external torx head.

[johnung]

Originally Posted by Logicoeur

It would be impossible to powdercoat/rebuild the caliper then. There are plenty rebuild kits (even from Brembo) so I doubt it is meant to be unserviceable

The calipers can still be rebuilt. The pistons, seals and dust caps all remove from the inside. Brembo told me that the fasteners that hold the castings together are not to be removed. I think I was trying to find out their torque spec at the time.

FYI- my bathroom scale did not work to try to get a weight on the wheel & tire. Electronic and bouncing all over the place

[Logicoeur]

Originally Posted by johnung

The calipers can still be rebuilt. The pistons, seals and dust caps all remove from the inside. Brembo told me that the fasteners that hold the castings together are not to be removed. I think I was trying to find out their torque spec at the time.

FYI- my bathroom scale did not work to try to get a weight on the wheel & tire. Electronic and bouncing all over the place

Ah yes you are correct if it's already unpainted. But how can you strip the painted calipers for new paint without removing the crossover seals? Since I had to redo my calipers a few times we had to dunk them in acid to get the coat off. The crossover seals definitely started to melt

[johnung]

Originally Posted by Logicoeur

Ah yes you are correct if it's already unpainted. But how can you strip the painted calipers for new paint without removing the crossover seals? Since I had to redo my calipers a few times we had to dunk them in acid to get the coat off. The crossover seals definitely started to melt

True. I forgot about the crossover seals. My powdercoater media blasts the calipers before recoating. Acid dunking seems pretty hardcore. He does dunk certain items depending on what it is.

[Sam!]

Originally Posted by Billfitz

Post a picture of one of the bolts you removed. It appears to be an external torx head bolt, which are rare but not impossible to find. If that's the only thing about it that's out of the ordinary you can probably substitute a bolt with the correct length and threads with a different head if you can't find external torx head.

Yup, looking for bolt specs even if there's no direct replacement.

The rebuild kit actually include replacement o-ring for crossover, no way of exchanging without taking apart the caliper.

[Billfitz]

The bolt specs are easy to find. Walk into any hardware store and match up the diameter and threads to one of the good bolts.

[WDE82]

Originally Posted by Sam!

Hi all,

In the process of rebuilding calipers, of course one of the caliper bolt was seized. Anyone know where to source a replacement? Looking for the bolt circled in red.

These don't need to be removed at all and they shouldn't be removed. I guarantee you're wasting your time replacing the seal in there.

Originally Posted by Logicoeur

Ah yes you are correct if it's already unpainted. But how can you strip the painted calipers for new paint without removing the crossover seals? Since I had to redo my calipers a few times we had to dunk them in acid to get the coat off. The crossover seals definitely started to melt

Um you sandblast them? Who the fuck acid dips calipers?

Originally Posted by Billfitz

The bolt specs are easy to find. Walk into any hardware store and match up the diameter and threads to one of the good bolts.

Hardware stores don't generally sell grade 10 hardware and IIRC these are a somewhat strange size. Even McMaster-Carr doesn't have them.


Solution to this entire problem: Don't remove these screws. Simple.

[Logicoeur]

Originally Posted by WDE82

These don't need to be removed at all and they shouldn't be removed. I guarantee you're wasting your time replacing the seal in there.

Um you sandblast them? Who the fuck acid dips calipers?

Hardware stores don't generally sell grade 10 hardware and IIRC these are a somewhat strange size. Even McMaster-Carr doesn't have them.


Solution to this entire problem: Don't remove these screws. Simple.

Idk. That's what the shop did to remove the powdercoat because they painted the mounting threads too.

[Billfitz]

Originally Posted by WDE82

Hardware stores don't generally sell grade 10 hardware and IIRC these are a somewhat strange size.

It's a brake rotor, not a GE90-115B. I can't see more than a Class 10.9 (that's how metric bolts are graded) bolt being required, especially as it's only one of four. It may not be possible to get an exact match, but it shouldn't be that difficult to find a bolt that will work.

[WDE82]

Originally Posted by Logicoeur

Idk. That's what the shop did to remove the powdercoat because they painted the mounting threads too.

Originally Posted by Logicoeur

Idk. That's what the shop did to remove the powdercoat because they painted the mounting threads too.

Oof they painted the threads? Never paint threads.

Originally Posted by Billfitz

It's a brake rotor, not a GE90-115B. I can't see more than a Class 10.9 (that's how metric bolts are graded) bolt being required, especially as it's only one of four. It may not be possible to get an exact match, but it shouldn't be that difficult to find a bolt that will work.

These are calipers not rotors. And that screw shouldn't be removed anyway. No need for a replacement.

Yes yes I know how hardware is graded. The shit at most stores is not grade 10.9. It's shite.

[Figgs_1979]

Originally Posted by WDE82

Oof they painted the threads? Never paint threads.

These are calipers not rotors. And that screw shouldn't be removed anyway. No need for a replacement.

Yes yes I know how hardware is graded. The shit at most stores is not grade 10.9. It's shite.

Find an industrial Fastener retailer. You'll find the bolt you need.

Utilize a thread gauge to determine what thread is required for a replacement bolt.

Yes totally fine splitting calipers as alot of rebuild kits come with internal O-ring that requires removal of bolts to change out.

Strip the old coating off via sand blaster ensure all the holes internally to caliper are protected. No need for acid stripping

Coat each caliper halve with desired coating.

I always polish my pistons with 2000 and 3000 grit on a drill press with a diy holder I made up.

Rebuild seals and Reassemble using medium loctite or red loctite if you never plan on redoing them again.

If you did not coat the new bolt heads a good rust Corrosion method is to Black oxide treat them or Paint the bolt heads after you assembled the rotor.

just my 0.02

[WDE82]

Why are we still talking about sourcing a bolt that isn't missing in the first place?