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I have a broken hydraulic caliper and am wondering if it can be fixed? Can I buy the half that the broken mount is on or would it be better just to buy a new one?

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    Out of curiosity: did this happen during actual braking, or did a stone hit the caliper, or what went on there? — The consensus answer is almost certainly going to be: don't risk your life, just get a new one. I would maybe give it a try bodging it with epoxy, but only as a temporary solution and only if I can check that braking doesn't put much shearing load on the joint (which I wager it probably does). – leftaroundabout Aug 6 at 16:06
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    Safest thing to do is replacing the caliper. And unless you have proper skills to do it, it should best be done by a qualified bicycle mechanic since it is a potential life threatening issue. – Carel Aug 6 at 16:19
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    Paul, I don't think you're asking about gluing it back together... do you mean buying one complete half of the caliper, as they are made of two halves bolted together? It needs disambiguation; I think that's the implication, but commenters aren't up to speed yet – Swifty Aug 6 at 16:39
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    @leftaroundabout even suggesting the the idea of 'bodging it with epoxy' is ludicrous. – Argenti Apparatus Aug 6 at 18:07
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    I bought the bike as a project bike and the caliper was not attached and I did not realize that it was broken so I do not have the broken piece. – Paul Aug 6 at 18:42
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I highly doubt you'll be able to find a separate alloy casting to replace the one that broke. Even if you can you'll be faced with assembling the caliper which is not trivial.

Just buy a replacement caliper. Make sure you refill/bleed the hydraulic fluid according to Shimano's documented procedure, of have a competent bike shop do it for you.

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  • I agree that gluing it or fixing it is not as solution i should try. I was not able to find just the caliper but think this might work: amzn.to/33xrllt – Paul Aug 6 at 18:41
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    @Paul Do you have a local bike shop nearby? There’s a chance they might have a replacement caliper lying around, or even a disassembled one they use for parts you can scavenge from. – MaplePanda Aug 6 at 19:06
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It is a brake - a critical safety component. Just replace it.

Any fix or hack or bodge could fail you at the worst moment, endangering you and others around you. This one has already broken, who's to say the rest of the casting is any better?

If it helps the acceptance process, find the cheapest brake caliper that you would accept. This is your Sunk cost, what you HAVE to spend. Then subtract that sunk cost from whatever the ideal brake's price is, and that's your UPGRADE cost, so the amount you choose to spend to get something fancier/better/etc. A $100 brake is really only costing you $40 more than the minimum $60 brake. (self-deluding mind games, also useful on any non-cyclist life-partners)

Just replace it.


If money is an issue, it may be reasonable to buy a used brake from ebay/gumtree/craigslist/trademe or whatever. But additional risks include damage from previous owner - you don't know what's happened to it.

For piece of mind I'd go with a new caliper, doubly so on the front where 90% of your braking happens.

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    I'd also inspect the mounting points on the fork/rear triangle and the mounts where the caliper should be attached for any damage. The alignment may also have suffered if the caliper was broken off by crude force. – Carel Aug 7 at 15:51
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    Good point about checking the mounting points. – Paul Aug 7 at 19:42

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