I’ve just replaced my brake pads and both of my brake levers started to leak.
I bled the brakes before winter using a bleed block and they were fine.
(for anyome wondering this is not my first time bleeding brakes)
A few days ago i reset the pistons and replaced my pads and the levers started to leak.
The brakes are shimano br m8000s.
by Extreme-Elenator9202
3 Comments
All good things must come to an end… seeing this more and more, I’ve pulled apart couple out of curiosity and I think I could find seals but it would be cheaper to replace. That being said, they all still worked just fine.
I’m going to make an educated guess as to what happened: You bled your brakes, and then sealed the calipers and then pushed your pistons back to make space for your new pads.
This procedure isn’t a problem with a lot of brakes, but Shimano brakes have a very delicate diaphragm that bursts very easily. That’s what has happened to your brakes more than likely.
I’m a bike mechanic and we see this problem a lot in the shop. We never touch my pistons without a funnel on the lever. But also worth saying, it really isn’t your fault, it is poorly designed. It is a weak point in an otherwise good braking platform. I’m sorry, this is a crap thing to happen, but it really is a bad design, and not a reflection on your capabilities as a bike mechanic.
Not an uncommon issue with these levers. You should remove the bleed screw before resetting the pistons. Replace the levers.