Leaking brake caliper

[Beancounter]

my last outing on the bike was at Bike Park Wales. At the end of the day the brakes felt a little spongy, nothing too bad but I don't like a lot of lever travel so it's something I needed to fix.

Life got in the way so I only had a chance to look at the brakes last Thursday evening. To my surprise, my front caliper was leaking fluid from the top piston:

https://youtu.be/lMfwwYK32bU

Got the caliper off the bike and using the compressor was able to get the top piston out which as you can see had broken into several pieces:

Shimano Caliper 1.jpg (99.37 KiB) Viewed 273 times

Shimano Caliper 2.jpg (227.5 KiB) Viewed 273 times

[Rockburner]

Plastic pistons?

[Beancounter]

Plastic pistons?

Yup. I’m stumped on why it broke. Also, no seals, just calliper body and piston.

£50 for a new caliper.

[Taff]

Plastic pistons?

Ceramic I believe. They are known to crack and split if they aren't pushed back into the caliper square and jam, which is really quite easy to do.

Have you found a replacement yet?

I've got an old 2 pot xt caliper in the shed if that's any good for you as a temp fix.

[weeksy]

Shimanos leak at the calipers. It's not uncommon

[Le_Fromage_Grande]

TBH at £50 for a complete caliper I wouldn't worry about it.

[Beancounter]

Plastic pistons?

Ceramic I believe. They are known to crack and split if they aren't pushed back into the caliper square and jam, which is really quite easy to do.

Have you found a replacement yet?

I've got an old 2 pot xt caliper in the shed if that's any good for you as a temp fix.

Thanks Taff but I’ve got a new caliper on order, should be here by the weekend.

Shimanos leak at the calipers. It's not uncommon

Genuinely never heard that before. Must say, it’s not a comforting thought that it’s not uncommon.

TBH at £50 for a complete caliper I wouldn't worry about it.

Agreed, stacking the bike into a tree would be a lot more expensive.

[weeksy]

Plastic pistons?

Ceramic I believe. They are known to crack and split if they aren't pushed back into the caliper square and jam, which is really quite easy to do.

Have you found a replacement yet?

I've got an old 2 pot xt caliper in the shed if that's any good for you as a temp fix.

Thanks Taff but I’ve got a new caliper on order, should be here by the weekend.

Shimanos leak at the calipers. It's not uncommon

Genuinely never heard that before. Must say, it’s not a comforting thought that it’s not uncommon.

TBH at £50 for a complete caliper I wouldn't worry about it.

Agreed, stacking the bike into a tree would be a lot more expensive.

Ping your start post up on STW and see the reaction you'll be shocked how many complain about leaky calipers.

[Beancounter]

Ceramic I believe. They are known to crack and split if they aren't pushed back into the caliper square and jam, which is really quite easy to do.

Have you found a replacement yet?

I've got an old 2 pot xt caliper in the shed if that's any good for you as a temp fix.

Thanks Taff but I’ve got a new caliper on order, should be here by the weekend.

Shimanos leak at the calipers. It's not uncommon

Genuinely never heard that before. Must say, it’s not a comforting thought that it’s not uncommon.

TBH at £50 for a complete caliper I wouldn't worry about it.

Agreed, stacking the bike into a tree would be a lot more expensive.

Ping your start post up on STW and see the reaction you'll be shocked how many complain about leaky calipers.

Kinda regretting buying another Shimano caliper - I thought mine were leaking because of the cracked piston.

[weeksy]

thing is... there's MILLIONS of Shimano calipers out there in the world... and 'some' have issues... but it's handfuls, not 50%...

I wouldn't worry.

[Taff]

thing is... there's MILLIONS of Shimano calipers out there in the world... and 'some' have issues... but it's handfuls, not 50%...

I wouldn't worry.

Exactly this, the number of reported failure is going to be tiny compared to the numbers out there in the wild.

From what I can tell, all makes of MTB brake calipers have their weaknesses whether that's in reliability, power, feel, fade, pad rub etc.

[Mr Moofo]

Buy Hope - you know it makes sense

[Beancounter]

Buy Hope - you know it makes sense

If only I could justify them.