I’ve bled my brakes and reset the pistons a few times before, but this time 1 of the pistons was very far out and was very hard to push back in. When I managed to push it back in to the extent you can see in the picture, I found out that it would leak oil. Is this fixable w/out needing to get parts? I read some other questions like this, but I wasn’t sure if it would apply to here.
If I accidentally broke the piston, where could I get another to fix it, or should I just replace the whole caliper? If I do have to replace the caliper, what would you guys recommend that’s just as strong or better for an electric gravel/adventure/road bike?
Also thanks guys for everyone being so helpful whenever I’ve asked for help here.
by GravelBikes
8 Comments
Had Shimano pistons extend too far out & seals that just failed. If you are comfortable with bleeding, you can easily swap out the caliper with a new one (same or an upgrade) then bleed out the air. It’s pretty easy to do & prices on calipers are reasonable. Had good luck with Universal Cycles. There are also some aftermarket brands that offer just calipers but you need to get ones that are meant to use mineral oil.
If you’ve got the hydraulic fluid handy, you could dab a bit around the edge of the stuck piston and continue to move it out and in. It might lubricate it enough to keep it going for the time being, but failing that you’ll need a new caliper.
Bummer news. Shimano arent designed to be repaired, but thankfully mt200 calipers are dirt cheap
By pushing the pistons without opening the lever reservoir you are creating a lot of pressure so it will leak. Just open the lever reservoir and then try.
I’ve seen several ceramic pistons break
Always, ESPECIALLY with ceramic pistons, leave the pads in and push against the pads. This will spread the pushing force out evenly and help the piston go in straighter
You MIGHT be able to find a new piston. Not sure if shimano sells them solo
Replace the caliper. shimano doesn’t really do serviceable stuff. Get a 4 piston caliper.
These break so easily. Buy the aluminum ones off Amazon and rebuild the caliper.
I have the same model for road bike. One of the ceramic piston cracked inside the caliper and started leaking. I had to replaced the the piston (kept the original gasket) with aluminum one I got on amazon for $20. Fixable but had to completely disassemble the caliper to pop the piston out, it was quite the hassle.