How To Clean Hydraulic Brake Pistons - Tech Tuesday
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- čas přidán 23. 04. 2018
- Prevent "sticky pistons" by cleaning and lubing the pistons every time you change pads. We talk a bit about how the brake functions and walk through the cleaning procedure to help your brakes in the long run.
Questions or comments? Leave them below!
➤ Tools & materials used:
• PP-1.2 Hydraulic Brake Piston Press www.parktool.com/product/hydr...
• DOT fluid or Mineral oil ( use the same hydraulic fluid in your brake)
• Cotton swabs
• Isopropyl alcohol
➤ Fix It:
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• Visit our CZcams Channel: / parktool
• Visit the Repair Help section of Parktool.com: www.parktool.com/blog/repair-h...
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![Fixing a stuck bicycle disc brake piston [1019]](/img/n.gif)
I always wondered how hydraulic brakes self adjusted. It's beautifully simple. Great explanation!
I think they're simplifying the explanation here. Also have to remember the oil reservoir on the master cylinder, its open to the cylinder at the resting position, but closed off during motion. This means as the master cylinder returns, just before returning to rest the system becomes open and oil pressure is relieved; so the slave pistons don't get fully sucked back to where they started.
At the same time, the flexing seal means there's preferential for the slave pistons to slip more in one direction than the other.
Both things need to work together for the pad wear compensation.
@@adriansue8955 yes thanks so it is a two sided story.. The pressure side and the relaxing side. Nice to get more understanding
@@adriansue8955 I think the way it works, is that the seal can also flex a bit in the other direction. Only when the master cylinder piston returns past the reservoir timing port, the caliper piston seals can relax to the middle position.
2:43 *alcohol for our alcoholic friends*
Funny guy! :))
I came to the comments for this
Lol wanted, to write same thing ;)
..that is ethanol !. Surely a cheaper and better option would be isopropyl alcohol and save the ethanol for a G&T?
Could i also use regular brake cleaner or lighter fluid for the cleaning part?
This was super informative! I always thought the pistons moved back because of the vacuum in the chamber when it is pushed out, but it was the seals that were doing the jobs all along~
Another Tip: Keep an old set of pads around as a maintenance pad set. Allows you to push the pistons back in without damaging the piston faces if using a flathead screwdriver/chisel/etc.
Use plastic tire levers :)
Ha. Good idea. I keep my plastic levers in the road kit. Have the Park metal levers that've never let myself down.
Was wondering if it was necessary to invest in the parktool piston press that they use here. I tend to bodge it with my metal tyre levers and always scratch the surface.
Simplest and least damaging is the box end of a cheap 10mm wrench. I say cheap because expensive ones have a huge width. Cheap ones will drop between the pucks. And if you have old Hayes post mount brakes, the box won't break the post
@@s31720 I use a wooden paint stir stick. They are firm enough to do the job, soft enough not to damage the pistons. Stick one through the caliper and pull with both hands
A 3mm Allen key in the calliper slot where the rotor is positioned will stop the pistons from popping out. (4mm Allen for Sram).
This way all the pistons can be cleaned.
If disassembling the calliper then this method is great for getting the pistons completely out to check the seals
I never knew this!! Amazing and extremely underrated comment.
The illustrations and animated graphics are incredibly well done. Give that man a raise! 😀👍
No one,,,, and I mean NO ONE!! has ever explained and shown what actually goes on inside a caliper like y'all did. I feel as if a light has finally been turned on in the braking department of my brain. Thank guys.
Another tip. Anti-bleed the breaks if the piston doesn’t quite go all the way in. Unscrew the bleed port on your break handle slightly and push the piston in a little bit. Let a couple drops of fluid out. A little goes a long way so don’t push too hard on the piston.
Great tutorials guys! But mostly I just watch these for entertainment!
It's Tomi again ;-p
Tomi Saaranen it sure beats watching todays politics ....but then its our duty to know what is happening out there because we live in dangerous times . I'm new to hydraulic brake calipers without the internet id be stuffed. its these dam pistons that confuse me . my shimano pistons from 2014 models are just plastic looking black ones without any rubber Orings? all the others iive seen have ceramic white pistons and rubber orings. so on striping the caliper and opening it I thought I may have lost the white ceramic ring part but no there isn't any white ceramic on this model just a black one?
Very well done guys. One item of note, if you have a Shimano brake with ceramic pistons do not use any metal tool to cycle the pistons. Also you have to be very careful to push on the center of a ceramic piston as to not get it sideways. With ceramic I will usually leave the old pads in to protect the piston while I cycle them.
I made a mistake, I pressed too hard and the pison came out, I put it back on but it caught air. and after a while I started to lose the mineral oil from the Shimano hydraulic brake. Please help me and explain to me how to proceed to put the piston back so that I do not lose mineral oil again. Thanks!
@@David_SPN put it back and then bleed the brakes
@@David_SPN You can't put the pistons back without losing the mineral oil or brake fluid. After cleaning the piston and placing it back you'll need to bleed the brake.
what material is the back of the pad made of? metal. that tool is flat as a pad, so I guess is as safe as a pad to push pistons back.
Killer video, a huge step I've been neglecting. Sorry wifey...gonna be in the garage tonight!
Great information in this video. Thanks for taking the time to produce this .
Excellent Park Tool®. We need more of these. Kudos to the graphic artist
Best bicycle maintenance tutorials i've seen, thanks guys :)
Woah, this video was uploaded the moment i sat down to clean my brakes, what a coincidence :O. Thank you very much very informative and fun tutorial!
I love this guy talk. Looong and simple at times.
You guys sure "sealed" the deal with this video.
Thanks for making this fun to watch as well as informative! You guys are great. And it really helped that you talked about one caliper moving less than the other because I have this exact same thing going on. Thanks for the help! And I'm subscribing to this channel now.
Before last piston push in I suggest cleaning oil from the piston surface as it will attract dirt and make it sticky again quite quickly.
I'm also in the camp of after the cleaning process to remove excess oil with brake cleaner or alcohol so that dust won't collect.
Agree, this will prevent unintentional oil transfer and pad/disc contamination.
Best explanation of a very common and eventual problem for most anyone. Great visuals!
Good tips.
I’ll be employing those at work soon.
Thanks.
Nice demonstration guys...
This are superb tutorials/info! Thank you
Great instructions, explanations (including graphics). Helped us getting hydraulic break pistons cleaned and brake pads replaced! Thank you!!
Very informative on how to correct those sticky pistons. Thanks
Why not clean the Piston initially with rubbing alcohol, then go to using the mineral oil/ dot fluid when working the piston back and forth? Feel like alcohol does a better job initially removing the dirt...
Awesome video. This is the kind of info that’s difficult to find. Thanks for making it easier for us!
Wonderful video as usual. Thanks Calvin, thanks Trueman
This was really helpful. Thank you.
Thanks guys... this cleared up alot of questions I had.
GREAT explanations! Thank you both!
Thank you for the info. Learned a lot on how to clean my disc brake pistons.
Fantastic videos! Congrats!! Super useful!!
Excellent work. Thanks y'all!
You guys are brilliant!! Thank you!
You just gotta love these guys.
Excellent as always. Thanks!
Always informative and entertaining. I love your channel.
This is fantastic! I've been changing my pads and aligning my rotors for years, but never thought to clean and lube the seals. Pesky seals! Thank you,
Ty for ur time to upload this video.. ty guys
Had a sticky seal on my wife’s recumbent trike. Was able to unstick it with the help of your video. Thanks guys!
great! really helpful !!! Thanks guys really enjoy the maint. tutorials.
Brilliant video, I had a lazy seal, was really messing with my head until I watched this. Many thanks guys.
Great tutorial guys, thank you!
Excellent explanation guys thank you.
Thanks for your help. I just bought a maintenance stand so I can fix everything myself, with your help.
Fantastic video!
I’ve just performed this job after shying away from it for years!
Thank you!
Very, very helpful. Thank you guys!
So lovely maintenance ❤️
Great tutorial.👍
Nice tutorial, I have a lazy seal on my front brakes and now I'm Confident to tackle the problem.
Muchas gracias por su aporte! Realmente se agradece, es simple y me parece que está muy bien explicado. Tanto la animación como el capiller recortado es de mucha ayuda para entender como funciona el sistema. Saludos desde Argentina. Comenzaré a seguirlos.
Well done guys. Thanks to this video I was repair a lazy piston yesterday. Felt great knowing what to do and your enthusiasm works really well.
Thanks again.
you of the Park Tool are very well understood know what they do and the tools are appropriate
Terrific job explaining how the pistons work and how to clean them. But, that seal clap and bark is everything! I had to watch the beginning of the video a couple more times. 😆😆
Solid info guys!
Thank you guys,this was the tutorial i was looking for:)
Cheers fellas. Sorted my sticky pistons out nicely! Great advice :-)
Great video. This is the problem to my hydraulic brake now. Thanks
Great educational info! Feels like a father and son video 😀
That was a great presentation. Very detailed with cut away parts. I had squealing brakes but after 3 repeated pad/rotor cleaning and scuffing it still squealed. After your video I checked the pistons and found they moved very little and did not retract. Followed your procedures and now they move properly. Voila! The squealing is gone. Big thanks guys.
thank you so much park tools
Fantastic intel!
Informative and entertaining.
Thanks
I’ve used some Pad grease as is used with Motor vehicle Brakes and I have improved feeling through the lever as well as the eradication of sticking Pads and noisy metallic scraping from the Cycles Disk Brakes.
You two are the best.
Quality video. Thanks for posting
I think this helped with a brake centering issue I was having. My rear wheel was almost rubbing on one side with more daylight on the other, but the rotor was centered in the caliper. After adjusting the caliper or pressing in pistons it would just happen again later. Today fixed the sticky piston on one side and now I see even daylight on each side. Maybe the better-moving side was squeezing out too much each time I tried resetting brake alignment, while the sticky piston wasn't out enough yet. I don't know if it would actually work that way, like I think it would have to almost slightly and temporarily bend the rotor from one side while braking for the piston to remain stuck out too much. I'm running thought experiments in my head while tired and I'm a maintenance newb anyway. Maybe I did something else that fixed the centering... but I think it was this.
right on the spot! this is what i am searching for.
Very informative! Thanks
Thanks a lot, that’s what i was looking for to fix my hydraulic break 👍🏻
Just what I needed!
Excellent video!! Thank you!
Great tips, sorted out my sticky brakes in no time
Great video, very comprehensive. From my experience water and mild soap works better to remove both brake fluid and mineral out. Furthermore, I would also mention how the reservoir works and how it gets isolated by the master piston before pressure build-up. Many people still think adding more fluid to the system than intended will reduce the dead stroke.
you couldn't make it better!!
Thank you!
great info, well done! just felt like this vid was made to entertain toddlers
Wow, thank you so much :)) I've been told to use silicon grease to lube the piston. But know, thanks to you guys, i know that i can use brake oil to both clean and lube the piston (and also know how the system work too).
P/s: i know with mineral oil is fine, but i don't think you should use the same method for DOT fluid braking system, cuz DOT oil is a little bit too harmful.
Amazing video
Thank you guys! Subscribed!!
I thought I needed to replace my brake pads and rebleed the system after about 500 miles of mixed riding. I cleaned my pistons and they work like new! Thanks guys. This was the answer.
So glad i watched this great info my dudes!
So working on your bike's brakes is a two person job! Awesome!
nothing better than scientific explanation, massive thank you
Very entertaining and good info!
thank you guys!
The very last bit might help me out, I have one side that moves a fair bit more than the other so moving the caliper should help. Crossed my mind to try that 👍👌☺️
thank you so much for the tutorial, the inner piston was rubbing the right part of the rotors then when i did this tutorial it actually worked!.
Thanks you guys.
This was not the video I intended to watch... but I'm glad I watched it. You guys are solid af. lmao :)
Great tips. Been working on bikes for how long and never saw an explanation for why one piston might want to move more than the other.
for me its more like, I've never seen an explanation for why they should want move in synch in the first place. There's no mechanical coupling between them, and fluid's going to take the path of least resistance. So in my mind is a miracle that they'd even be as close as they are.
@@adriansue8955 the fluid isn't taking any paths of least resistance, as the resistance is the same on both sides of the pistons. Theres the same amount of gap for the fluid behind each piston. So whats happening is even pressure is being applied to each of the calipers, its just up to the seal to bring it back after pressure taken off,
@@akeluify "the resistance is the same on both sides of the pistons"
...in lab conditions when both pistons are brand new. And even then there will be differences resulting from how each seal interacts with each piston. Once they start picking up dirt these differences will increase and each side will retract differently.
Gold video!
Great info thanks
nice job guys
Life savers! Thanks!
Thanks for that. Couldn’t get my back wheel back in and had no idea why or how to adjust the brake pads (I knew where I was with v brakes). All sorted now!
Thanks for the vid. Useful info
Dropping knowledge like it's nothing. Thank you :)
Very informative. Hydraulic disc brakes are a pain though. They stop with amazing precision but there are a number of components to maintain. The part I am having a problem with is reaching the pistons while I have the brakes compressed.
They cut apart a caliper for people to understand better. I love these guys