How To Bleed Any Hydraulic Bike Brake

[@strayedcat1966]

WOW! It doesn't get any more thorough that this! Outstandingly masterful!

[@jimrutherford2773]

Probably the best video I've seen on subject of brakes, how they work, and bleeding them.

[@gmbntech]

Thanks a lot, Jim! Doddy did a great job at explaining everything! 👍

[@thephoenixcycle8854]

I had a supremely stubborn pair of Shimano M9100s the other day. What I finally had to do was inject oil, with great force into the master cylinder to clear out the a-hole bubbles, stuck in the caliper. You can't be friends with these brakes. You got to be forceful right away and show them who the boss is.

[@Julianhulls]

Don’t force it, get a bigger hammer!

[@Derkenblosh2]

Just get the wife's vibrator to shake those bubbles lost

[@SyhrMr]

You need to vacuum bleed the caliper by pulling the lever into the bar to seal the system from the reservoir, and drawing a vacuum with the syringe connected to the caliper, also orientating the caliper bleed port to be the highest part of the caliper, and tipping the caliper side to side helps.

[@ccarlock8537]

Cause the oil has wax particles that the air sticks to. I kissed the pads and got rear but front had to set for a week till got the bubble out

[@matthewmoodie6553]

🤣

[@hyperslow556gungamer]

Bubble behind the caliper piston shelf: As you bleed, while moving the lever to move the pistons while bleeding a magura Trail system, tap on the caliper with the hard plastic handle of a screw driver while moving lever around while bleed reservoirs are installed.

[@devinmadren1819]

Yes it exactly this. Those bubbles stick.

[@kevinw6282]

Nice comprehensive review, covered the vast majority of it for sure! I think one good rule of thumb is to avoid bleeding through any process that puts the system under vacuum, which doesn't really fit good bleeding practice but at times may be tempting. The issue is with the hose connections on syringes to the fittings or the syringe itself. These connections can allow tiny air bubbles to get in when under vacuum and then you may introduce very tiny bubbles to your fluid that you may then push back into the system. As a rule I think it's best to never try to suck fluid through by pulling on syringe plungers and that avoids the problem altogether. If you only ever let fluid in passively via gravity or by pressurizing the system I think the odds of accidentally adding air are prrety small (as long as the fluid you start with is completely bubble free).

[@wydra9-1]

I see what you mean, though SRAM's own bleed procedure is to place it under vacuum unfortunately.

[@left0verture]

Thanks for convincing me that this is all over my head. I’ll take my bike in to the shop for this process.

[@Too_Goated1]

no not really, i’m 14 and can bleed my own brakes. his video is just a more in detail and complex explanation

[@mikeneitte212]

@@Too_Goated1 that is the reason I prefer to read instructions rather than listen to someone else..they may use a LOT more words than I need..

[@Toby-sb5nc]

Literally bro way to complicated🤣

[@kalijasin]

If you make even the smallest or tiniest mistake in doing this it will all goto hell and you will be out whatever you paid for your fancy hydraulic disc brakes.

[@alanhaze3192]

I've used my battery razor to great effect to vibrate those capillary bubbles out

[@markthomasson5077]

Good idea, but I have a beard. Hey maybe my wife could help!

[@ShinySideUp76]

@@markthomasson5077 lol

[@ThunderStruckMTB]

Missed the very important step of cleaning the pistons, opening the system at the lever so the fluid has somewhere to go and the diaphragm doesn't tear, and then pressing the pistons back into their bores so the bleed block actually fits between them.

[@piczonman]

The most thorough explanation of the topic! Cheers.👍

[@thomasnowsun]

Thank you! I don't think I ever came across a video going through all those details. I finally understood the few missing puzzle pieces I needed to elevate my bleeding skills. Fantastic job 👍

[@pw7752]

Don't forget to mark your brake lever positions before moving them! (Been there, done that)

[@dylan-5287]

Wow I forgot how good Doddy was. Such an in depth look into how brakes work let alone just bleeding them. Makes so much more sense when you understand what's going on below the surface.

[@CuzzyWuzzy]

Brilliant episode, very practical. Thanks Doddy 😁.

[@Simon1279.]

This is the best video about brakes that i've ever seen on the internet so far

[@scandinavianairman2220]

Automotive mechanic here. I use silicone grease to lubricate the pistons, as you would on a car if you have a stuck piston in the caliper. It works out really well! But my qualified guess would be that silicone grease for car brakes is only compatible with DOT mountainbike breaks. This made a huge difference on my breaks. (Older aviid elixir model)

[@devinmadren1819]

All.depemda on the ingredients compatibility between the grease and type of oring on the calipers. Swelling, ect...

[@yengsabio5315]

I don't do the bleeding myself. My trusted bike mechanics do it for me. But it's great to learn even only bit-by-bit out of this video, Doddy. I find it very informative. As my practice for maintenance, I have my hydraulic breaks bled annually. Lots'a love, cheers, & Mabuhay, from tropical Philippines! #RideOn #KeepBiking

[@MrSupermugen]

I've used probably 15 shops, none of them could bleed Sram correctly, learnt myself and they are so much better.... people hate on them because they cant bleed them properly.

[@gmbntech]

Yeah, sometimes it can be a lot easier to head down to your local bike shop to get your brakes bled. You know you're getting a quality service if you're not sure about the correct bleeding process. Thanks for the support, and safe riding! 👍

[@yengsabio5315]

@@MrSupermugen Surely, I'll gain the confidence of doing it myself in the future. It's just that it's not my expertise. But being in the shop watching the bike mech do the stuff, I think I can certainly learn it.

[@manueltzamalidis5266]

awesome thank you, there is just one thing i‘ve learned from working in the bike brake industrie. if you have 4pistons make shure they all move nearly simultaneously. especially with magura 4piston brakes it is key to a good and quiet brake😬👍

[@P6_7R_Nick]

I'm sure I'm not alone when I say it would be nice if GMBN Tech worked on some lower end, like proper budget stuff too. I'd have been very interested to see your technique on bleeding Clarke brakes. I'm sure there will be many others that can't afford a bike with mid to top end accessories but still love watching these videos. Keep us all involved please.

[@coler154]

I have the Gemma GA-1000 brakes and there are no bleed guides anywhere!

[@GSNorrie]

Very nice, concise upload. I was hoping it would mention SRAM's new DB8 mineral oil brakes as I just unexpectedly got them on my new bike (supply issues) and there's very little information on them so far. They are already spongy but this video has given me a few more ideas. Thanks.

[@Richard-ug4el]

Thanks for this video. I learned a lot. It was a nice, clear and concise guide to understanding hydraulic brakes. I'm been trying to sort out my brakes on my electric scooter, and watching this really helped me understand the system. I think I know how to correct the problem now.

[@SUBcyclist]

Excellent video, once again. Dodd truly is omniscient - with regard to bike tech!

[@gmbntech]

Thanks, Chuck! He truly is! 👍

[@noelfezza]

ABSOLUTE MASTER CLASS OF A VIDEO! DODDY YOU ARE ABSOLUTE GOLD! please never leave. You have no idea how much the industry loves and needs you 🤘

[@fibranijevidra]

Fantastic video. I've learned alot. Thank you.

[@dougstobaugh376]

Thanks for your educational experience and resources and support for replacing brake fluid. Hopefully, after watching, I will be able to take care of my brake system very through the video. God-bless.

[@willlange9978]

Outstanding tutorial! The cutaways provided next level clarity. And thanks for the extra mini-tips like tilting the Shimano levers back and forth. Thanks

[@gmbntech]

No problem, Will! The team did a great job bringing this video together!

[@hoff482]

Good info Doddy, thank you. After several mistakes, bleeding mine, I cannot stress enough the proper bleed block. I learned this after cracking a pot on my Saint breaks. 🤬 And of course I stripped the screw holding the caliper together. So, after replacing the entire caliper I have learned my lesson. 😁

[@Leo-gt1bx]

How did you break it?

[@SyhrMr]

High spec Shimano calipers have ceramic pistons to insulate the brake fluid from the heat coming from the pads and rotor. If you don't press them into the caliper squarely with a plastic tool, they can fracture as they are quite brittle.

[@pedrozampatti7172]

Hi everyone. I was searching for a video about how to properly flush your brake system and when it's recommended to do it. There's none. I'm a bike mechanic starting to work on e-bikes and for reasons beyond my control i can't get the recommended brake liquid for Tektro, which is the brand most bikes we deal have. Do i need to flush the system before refilling? I understand there are some tricks for improving the brakes just removing air bubbles from the system and filling some liquid in. Can i do that mixing brands? Your help will be highly appreciated.

[@benc.8103]

Thanks Doddy

[@paulgreen503]

Great Vid. One point I have issue with. You do not need two kits for DOT and Mineral. Just make sure you wash the syringes, tubes, connectors.

[@my_key]

Thanks for the info. Any tips or pointers on Tektro (Dot-fluid) brakes in future videos would be highly appreciated.

[@maximusmeridius1240]

Best tutorial ever , thank you .

[@andrewwhite1065]

I prefer the 2 syringe method, for not only replacing the mineral oil but more easily observing any air bubbles in the system. And its far easier to handle & less messy than the method you are explaining, at least from my experience.

[@1969Escobar]

Great video, thanks Doddy, merry christmas, cheers

[@chrisridesbicycles]

Very comprehensive overview. That‘s a good reference for years to come. Can you cut open a Shimano lever? I‘d see the proof that the bite point adjustment on those does nothing at all.

[@bobbyhempel1513]

But it definitely does.

[@SyhrMr]

It does, but it only increases the dead stroke which most people want to minimise and after making the adjustment, you have to correct for it by winding the reach adjustment, otherwise it doesn't seem like anything happens at all.

[@tomcot]

Great video. I was wondering about lubing the pistons - timely tip! Looking forward to the brand specific videos. Thanks.

[@gmbntech]

Thank you, Tom! Stay tuned. 👀

[@dangermouseanpenfold]

@@gmbntech Hiya, i wouldn't lube pistons generally on the outer side, clean yes and especially before fitting new pads (when pushing pistons back through the seals) (and during any caliper rebuild) doing that will just attract dust/dirt, as as you say in the video it is the the seals that help the pistons retract and thus they need to grip the piston. As the pads wear down they will edge out slowly through the seal, but in terms of brake on/off the piston movement is managed by the seal flexing in and out it is the reason they are square and there is some space around the seals in the caliper- same on cars/motorbikes. What we are missing as that a lot of larger app caliper have is nice dust boots that protect the exposed part of the piston.

[@Rustyfox46]

Nice one Doddy. Another great descriptive video - think I might have a go over the Christmas period. Just received my Epic Bleed kit for my Shimano brakes 👊🏻

[@bikoastal9203]

Best brake bleed video, ever. Seriously.

[@kaltonian]

brilliant doddy, love the cut out parts to showing how it all works, iv bled many a car break so hoping principles are the same.

[@otakarsindler6117]

As always excellent tech video from Doddy. Thanks. Btw: Message to Alex from GCN - Watch and learn...

[@BerserkerNick]

I'm running Magura MT7s and they were an absolute nightmare to bleed

[@owenjohn1192]

Same with the mt5's

[@lakaldrak]

Why ? Best way is do IT Shimano Style. 👍

[@zaantane4873]

Perfect timing for myself Cheers

[@gmbntech]

Perfection! 🤌

[@tadejpeckaj1151]

Great video Doddy!

[@selfhelp69]

You and Anna et all are just crushing it with content for DIY and local bike shops. I'm learning so much.

[@elibaxla5727]

Perfect! Thank you

[@antoniogalluccio4213]

Do I have to open the bleed port on the caliper while adding fluid from the top and pulling the lever? Some videos show that other just don't

[@thephoenixcycle8854]

Pintosin CHF 7.1 mineral oil is far superior mineral oil for Shimano brakes in my opinion, plus it's way cheaper and you get so much for your 25 - 30 bucks or whatever it is I paid for it

[@moreadventureuk]

An excellent overview!!!

[@Fudders]

Really helpful and clear. Thanks Doddy and team.

[@HUDDYWILLS]

This video taught me that my bike shop sold me a DOT kit for me to use with mineral oil brakes. It's a relief to know why my brakes are still spongy! Time to get a refund.

[@LECMTB]

Perfect video, I want to learn how to work on my bike myself, A it's a nightmare booking into shops these days as they are so busy and B l, at least I'll know how to fix my bike trail side. I'm going to attempt to bleed my brakes today. Thanks for the video it will help out alot 👍

[@christopherelliott-lyle7100]

Great video, thanks

[@Michi.108]

best explanation ever, thanks

[@gepeszifju]

Very informative video, thanks! A tiny correction: The bite point adjuster doesn't affect the distance between the pads and rotor. It only affects the dead stroke of the master cylinder's piston.

[@wallyedmunds2181]

An excellent video overall, thanks for that. I would agree with a previous comment about the "bite point" adjuster, which only moves the position of the master cylinder piston relative to the MC itself, at least to my understanding, and not the position of the pads relative to the disc. Slightly off topic, but it really pi**es me off as to why bicycles and motorcycles/scooters have the front brake lever on opposite sides. As a lifelong motorcyclist myself, any cyclists/motorcyclists out there will know what I mean! Thanks again for a really good vid.

[@johnzee691]

big thanks. going to attempt magura marta brake bleed but will likely pick up some shimano brakes to replace but want to try bleeding for the experience. this was a great video on what to expect, wetting my mind.... 😎👍

[@sirvince7853]

Thanks Doddy for another great video.

[@gmbntech]

Glad you enjoyed it Vince! Hope it was useful

[@goomanguy]

Really good info. I’ve just been on the shimano website as I’ve just bought some Deore brakes. I don’t know if they have updated website. But Deore and lots of other shimano are classed as ‘one way bleeding’ only need a funnel at the top to bleed.

[@robinschomer6547]

Thank you that was a very informative video you presented it extremely well and it was very helpful kudos

[@jornmulder]

very good video, thanks alot

[@papawoopty]

u say water come down... so mineral has to performe a 2 step... a down bleed 1st to escape water and old fluid ... then an up bleed to escape air ... 👌

[@oliveraidoo7861]

Thanks a lot for making this video. I have a question. Can the brake cable match with any brake caliper as well brake levers?

[@SurvivalSquirrel]

16:47 why pressurise the lever? It would disconnect the reservoir form the rest of the system.

[@nothere7300]

Excellent video thanks.

[@PeterMisovicProfile]

Thanks, very informative!

[@jesuscruz836]

This is the video I have been waiting for.

[@gmbntech]

Glad to have helped!

[@KP-ky1sn]

Great video. Easy to follow. Some unhappy, menacing, vindictive soul decided to cut my rear brake cable because they couldnt steal my bike. so I have to replace the entire cable. The whole replacement plus bleed kit cost me like eu100. Not cheap but I gotta do it because I can't wait 3 weeks for a booking plus the actual store repair will only save me eu20.

[@RichardMaguire110]

Thank you, very useful.

[@gmbntech]

Thanks for watching, Richard!

[@rench1984]

Cheers, just saved £50 at Halfrauds with this video. They want £25 a set to bleed brakes, told them to jog on. Great video! Thanks.

[@whiskeyrocknrolla4033]

Very informative, tha ks 😊

[@Frank-mn4hx]

I don't have the brands that you said in the video. The brand I have is TREK. And I use mineral fluid. I have a small bleed port on the top and I can't find any bleed port on the caliper. How can I bleed this system?

[@NiallBuckley-p4o]

I Cannot find any information on XOD-E300 brakes and which mineral oil to use and how to bleed top down or revers way thank you Niall

[@AnteBrkic]

I'll just get v-brakes on my next bike. Had them before and didn't have any issues for more than 10 years. Now with discs on the other hand...

[@armandocampamartinez8307]

This video came out exactly when I needed it. If I had a second hand bike that needed bleeding but didn’t know what type of mineral oil it had, how do I proceed?

[@Daftleat]

Absolute shreddin kings. Bossed it 🤙🏻 #Marra

[@RaceJan]

Excellent!

[@SchMadden]

@gmbntech whilst we know we can’t mix dot and mineral… can you show us what happens when you replace dot fluid with mineral in a brake and vice versa? Always been curious

[@SyhrMr]

Dot fluid attacks rubber, that is why special materials have to be used with dot brakes and why you see rebuild kits for dot brake calipers and levers, but not mineral brakes.

[@TheSpoovy]

I was with you right up until the "manufacturer specific bit" when suddenly my shimano brakes needed brake and caliper attention, bucket and syringe, or syringes at both ends, bleed bottom to top, then back down again... wtf?! 😆

[@tmhudg]

I agree with you that this is the place where it went off the rails. Having seen other bleeding videos, I knew what he meant by bottom to top and then top to bottom but it certainly wasn't explained here. Kinda surprising because everything up to that point was fantastic. Maybe they think you will find brand-specific videos and follow those and this was more of an intro/overview.

[@JesRobles-b9x]

You missed the tektro brand. Do you bleed from bottom to top? Or vice versus? Thanks

[@bfocht2]

Great video. I have a "not-a-wheelchair" that uses Zoom hydraulic brakes. The front brake has a splitter so that both wheels can be stopped at the same time. Any ideas on how to attack the bleed on a split hydraulic brake? (The rear has only one.)

[@wesleynice3823]

If i want to bleed the front brakes, what do you mean top to bottom? The front wheel and left brake?

[@cestlevrairaplaoenothex8733]

I never overtight handles....considering better to move than brake if hit something

[@gmbntech]

Same here!

[@dimitarspasov1232]

Thanks a lot!

[@Alex-ph4iu]

Good and informative review👍👍👍 but what if i just wash my bleed kit with degreaser in orderder to use it with other kind of oil? For example: i bled brakes which run on mineral oil, washed the kit and now i can bleed with dot using the same kit, or not?

[@molley17]

Can anyone tell me why you have to adjust the reach out as far as possible?

[@Ffkvke]

Very helpful!! Thanks Doddy👍:)

[@gmbntech]

Glad this was useful! Thanks! 👍

[@edrussell7960]

Ok ive got a cannondale that is probably 2016, i dont see a bleed port on my brake handle. Ive pulled the cap off but i dont know how to bleed them as the cylinder in super shallow and as i try to cycle the brake it almost goes dry each pump. Ive been off of it for a couple of years. Im not real familiar with newer bikes systems. Its a 29 inch mountain bike if it helps. Thank you for any help. It also says dot 3 or 4 on the lid.

[@pobthecat]

Morning, Just saw the video. My main comment here is with the Magura brakes. Do not use the top syringe to pull the oil through the system! The top syringe should only be used as a reservoir to take the excess oil pumped up from below. by using the plunger in the top you increase the risk of destroying the reservoir cap by a sudden increase in pressure. If you are using a plunger in the syringe then only push it in until it sits a millimetre above the hole in the side of the syringe.The best way to start is with the syringe at the top simply pushed in the bleed hole in the master. How did you end up with the French/Dutch oil bottle in the UK? 😉

[@rider65]

Is this your own experience? Or from Magura engineers?

[@rider65]

Been using the syringe for 1 & 1/2 years now on my MT 30's. 3 bleeds, NEVER a problem bleeding from master cylinder. Me thinks you are MIS-informed.

[@pobthecat]

Morning@@rider65 "Engineers" & 20 years Magura Tech Hotline.

[@pobthecat]

Hi@@rider65 yeah if it works for you great. Many mechanics have their own tips and tricks that they use for years. This is not however what Magura says in any of the manuals on how to bleed a brake. ;o) Once the reservoir cap is off there is no way to repair it. there is no problem with the syringe at the top as long as it is being used as a reservoir and not to push oil into the brake. 👍

[@IOUaUsername]

Squeeze the syringe quickly, not slowly. The flow rate should be faster than bubbles would rise through the hose, making gravity a non-issue.

[@Altilagi]

Great video! I knew nothing about hydraulic brakes. Now I understand that I wont adjust them myself :)

[@MediumHalf]

Man the singer from Rammstein sure knows his way around mountain bikes!

[@josephwright7925]

Hi Doody any chance of showing how to replace the parallelagram on a rear deralleur, preferabally AXS. Everyone has a scratched one and i can not find a video on how to do it SOS Cheers

[@JohnnyC10071959]

braking master class

[@aasimmons]

Could you and Anna do a video where you swap dot fluid for mineral oil (and vice versa) to see how well or poorly the brakes perform?

[@pobthecat]

Hi AGS, it's not that the brakes perform poorly they just don't perform anymore. The results are different for many brands, but mainly the seals deteriorate and usually after swelling up so the pistons don't move anymore they end up turning into wet liquorice. The brakes are dead afterwards.

[@wtfvids3472]

if the exit point is on the top, the "hoses" are as vertical as possible, the break drums are all the way in(to get rid of air) and you push the new fluid in with the force of a thousand suns... can any bubbles be left in the system? im just thinking from a physics point of view here. Bubbles want to rise, but they can be caught by adhesion on the tube walls... but they will be entrained by moving fluid and go upwards and the greater the pressure from the bottom the likelier it is that they will be entrained.

[@modernclips4life960]

Could you please make a video comparing the mini e-revo and the hyper go. I just bought the mini e-revo but noticed in your other video the hyper go can go 39mph and the erevo went 41 or something. People would love to see them compared and I don't think there's a video like that..

[@yutehube4468]

It's taking the caliper off that's the bummer to me. Just to put a block in 🤔Surely 2 thinner blocks can be wedged in at each side of the rotor (with pads out) to stop the pistons moving. Whether the caliper is on or off, has no bearing on the bleeding process, but it can be a pain getting the caliper lined up again, so if it can be done without taking the caliper off it's a big time saver.

[@MichaelDarker]

Can anyone tell me why my MTB back wheel keeps locking up? It's the brakes, and I took it in summer before last to have them done, I want to do it myself this time but would like to know why this keeps happening...

[@cecil5887]

Please help me get The Resorvoir bleeding brake screws size M4x6 for Aniioki A8 Pro Max.The manufacturer don't have.

[@garethhughes3930]

Hi, great info, thanks. Quick question with Logan 2206 breaks, do you know if they are top to bottom or bottom to top. If it helps they are on an Engwe engine pro. Any help would be appreciated 🙏 😊

[@veejay2901]

Syringe won't move on Shimano caliper, is this caused by air? How do I fix as I have no brake.