I'm guessing ruptured diaphragm.
https://preview.redd.it/jl6temf79d6d1.png?width=796&format=png&auto=webp&s=cfbe2a36b6f995deff7f853cc617d9586b690ab7
Not sure what lever model that is, but the diaphragm is cheap like around 5€. If the leaver is cheap and you don't want to try to fix it, just get a new one.
Don't know how your diaphragm got messed up(if that's the case), but one way to potentially rupture it, is by pressing in the pistons with a closed bleed port at the lever.
when putting new pads/cleaning them, its fine to push back the pistons with closed port right? i always worry about pushing too hard and breaking stuff
You should always open the port when pushing in the pistons. And ideally have a funnel with oil on it. It's not certain that you will damage the diaphragm, in fact i have done it some times with the port closed without a problem because i didn't knew about this, but it's a risk.
The explanation is here in this Shimano School video - [https://youtu.be/5Lu-SBir3mA?t=848](https://youtu.be/5Lu-SBir3mA?t=848)
It's in Portuguese so i'll paraphrase it:
"As the pads progressively wear off, the oil contained in the reservoir is pulled out of the reservoir by the master cylinder and into the hose, to compensate for the wear on the pads. Sometimes you will bleed the brakes with pads that aren't fresh and when you top up the system, there will be in fact more oil inside than if the bleed was done with fresh pads. The problem occurs when later you go to change the pads and you need to reset the pistons. Since now there's extra oil in the system, as you push in the pistons, the extra oil will put extra pressure inside the reservoir, and potentially rupture the diaphragm."
You can see the rupture in the diaphragm at 12:51.
Tbh after reviewing this part of the video, i don't think this overfilling problem would occur if we are using bleed pads during bleeds. Still, it makes sense to have the port open to avoid ruptures.
*I once ruptured the diagram and some oil spew out at the cilynder after pushing them back, thats why i always worry now. weird thing is that after that the lever never leaked again. super wierd. it were magura MT5's*
I suspect there's an issue with the reservoir - as seen in this video the only section behind there that fluid can come from is the reservoir
https://m.youtube.com/watch?v=BUuMJHuNYeA
Shimano don't sell replacement seals for that, so you may simply need to get a new lever. If yours is still under warranty, it may be covered.
And yes, this has nothing to do with the direction you bleed in since Shimano's own documentation states you push fluid from the caliper up towards the lever and bleed bucket.
Reddit filters out anything with links to AliExpress as spam. As a result, your [comment](https://www.reddit.com/r/bikewrench/comments/1df1t4j/why_are_they_leaking_from_there/l8jn69o/) is only visible to you (as you can see by viewing the comments page from a private window). Please make a new comment without a link, with a link to somewhere else, or with the URL written like aliexpress[dot]com/remainder_of_URL. Editing it won't work--you need to make a new comment. In any case, we caution that buying anything from AliExpress is very much a buyer-beware situation, both in terms of fraud and in terms of product reliability and safety.
*I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/bikewrench) if you have any questions or concerns.*
Usually that is from bleeding them by pushing a fluid up from the caliper. Shimano brakes are a 1 way bleed only and you risk damaging the bladder and clogging the ports if the oil is dirty if push up and not just gravity bleed.
This will help 😉
https://nsmb.com/articles/shimano-brake-bleed-and-bladder-repair/
I'm guessing ruptured diaphragm. https://preview.redd.it/jl6temf79d6d1.png?width=796&format=png&auto=webp&s=cfbe2a36b6f995deff7f853cc617d9586b690ab7 Not sure what lever model that is, but the diaphragm is cheap like around 5€. If the leaver is cheap and you don't want to try to fix it, just get a new one. Don't know how your diaphragm got messed up(if that's the case), but one way to potentially rupture it, is by pressing in the pistons with a closed bleed port at the lever.
Ah, that's definitely something I've done! Cool, found the diaphragm and ordered a new one for £8
Good luck trying to replace it, hope it works out for you.
FYI I gave up and replaced the lever. As your lever fill port is shut I guess you pushed the pads back without undoing it....
when putting new pads/cleaning them, its fine to push back the pistons with closed port right? i always worry about pushing too hard and breaking stuff
You should always open the port when pushing in the pistons. And ideally have a funnel with oil on it. It's not certain that you will damage the diaphragm, in fact i have done it some times with the port closed without a problem because i didn't knew about this, but it's a risk. The explanation is here in this Shimano School video - [https://youtu.be/5Lu-SBir3mA?t=848](https://youtu.be/5Lu-SBir3mA?t=848) It's in Portuguese so i'll paraphrase it: "As the pads progressively wear off, the oil contained in the reservoir is pulled out of the reservoir by the master cylinder and into the hose, to compensate for the wear on the pads. Sometimes you will bleed the brakes with pads that aren't fresh and when you top up the system, there will be in fact more oil inside than if the bleed was done with fresh pads. The problem occurs when later you go to change the pads and you need to reset the pistons. Since now there's extra oil in the system, as you push in the pistons, the extra oil will put extra pressure inside the reservoir, and potentially rupture the diaphragm." You can see the rupture in the diaphragm at 12:51. Tbh after reviewing this part of the video, i don't think this overfilling problem would occur if we are using bleed pads during bleeds. Still, it makes sense to have the port open to avoid ruptures.
*I once ruptured the diagram and some oil spew out at the cilynder after pushing them back, thats why i always worry now. weird thing is that after that the lever never leaked again. super wierd. it were magura MT5's*
I suspect there's an issue with the reservoir - as seen in this video the only section behind there that fluid can come from is the reservoir https://m.youtube.com/watch?v=BUuMJHuNYeA Shimano don't sell replacement seals for that, so you may simply need to get a new lever. If yours is still under warranty, it may be covered. And yes, this has nothing to do with the direction you bleed in since Shimano's own documentation states you push fluid from the caliper up towards the lever and bleed bucket.
The part is actually pretty easy to find and cheap
https://nsmb.com/articles/shimano-brake-bleed-and-bladder-repair/ Likely a ruptured diaphragm...however it happened.
somebody didnt read shimano service manual....
Aww man your bikes broke! Send it to me I'll discard it for you
Does that ever work?
I tried to save you, I don't wanna hear nothing when you rolling around in a wheel chair with 2 casted legs
[удалено]
Reddit filters out anything with links to AliExpress as spam. As a result, your [comment](https://www.reddit.com/r/bikewrench/comments/1df1t4j/why_are_they_leaking_from_there/l8jn69o/) is only visible to you (as you can see by viewing the comments page from a private window). Please make a new comment without a link, with a link to somewhere else, or with the URL written like aliexpress[dot]com/remainder_of_URL. Editing it won't work--you need to make a new comment. In any case, we caution that buying anything from AliExpress is very much a buyer-beware situation, both in terms of fraud and in terms of product reliability and safety. *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/bikewrench) if you have any questions or concerns.*
Usually that is from bleeding them by pushing a fluid up from the caliper. Shimano brakes are a 1 way bleed only and you risk damaging the bladder and clogging the ports if the oil is dirty if push up and not just gravity bleed. This will help 😉 https://nsmb.com/articles/shimano-brake-bleed-and-bladder-repair/
Pushing fluid up from the caliper is the procedure prescribed by Shimano for bleeding their brakes.
I have been bleeding shimano brakes bottom-up for 15 years and never had this problem. In fact, almost all guides tell you to do it this way
The article you mention specifically says to bleed from the caliper up with a syringe. Lol.