Ceramic piston cracked. Smaller bolt loosened without any fuss. Larger bolt stripped.
Anyone know where to find a replacement for the bigger bolt?
If i use a bolt extractor on it that bolt will get mangled and useless.
Thanks!
FYI the brake caliper is a GRX br-rx810 and is identical to Ultegra br-r8070 i think
by bulbangs
6 Comments
Shimano do not sell any small parts for disc brake calipers, so you’re unlikely to find a replacement piston let alone a bolt. The easiest course of action would be to replace the caliper.
Looks like Shimano doesn’t sell a replacement for that bolt, as they don’t support this type of service of their calipers. Since that bolt is manufactured specifically for this application you will likely need to find another caliper to scavenge that bolt from.
There are a few titanium replacements on Aliexpress, though they’re for Shimano MTB calipers. It might be compatible, I’m not sure. Search for item 2251832769453028 for example, or 3256805000280977, or 3256805875740334.
Remove the bolt first and measure the dimensions. The one in the link is 24mm long (not including the head), M6 thread, 17mm thread length.
I would cut a slot in the bolt with a Dremel so you can use a flathead screwdriver to loosen and retighten the bolt.
it looks more like you use wrong size torx bit (too small), I’d try a size bigger first before cutting the bolt. And it’s just a bolt, you can easily find a replacement as long as it fits. Look up on AliExpress , maybe you can find a titanium replacement
Replace the caliper, shimano doesn’t really do service parts.