TECH TIP: Bleed Bicycle Disc Brakes Right the First Time Like a Pro!

[@JamesEllisPT]

This is the video I wish I’d watched 3 months ago! Every time I was doing a bleed I was having air in the caliper. Taking it off was the only way to get it cleared, and rotating the bike in the stand didn’t work. Thanks

[@DiamondbackAxis]

thanks! makes perfect sense

[@angustroutman3494]

Why not drop the ass end of the bike leaving the caliper mounted. Then rotate handle bars, so reservoir cup is level. Then push fluid from caliper to cup?

[@BBInfinite]

It's very easy to unbolt the caliper. Not sure why everyone wants to avoid something that's so easy.

[@HULKBIGHEAD]

The most comprehensive video on KZbin on how to bleed brakes correctly. I have watched so many videos and could not figure out how to get the air bubbles out of my rear DI2 brakes until now. Thank you so much! 👑

[@mayyuval]

Great demonstration, especially the beginning, to see the principal in action. Question - would that work also with a syringe connected at the pump, instead of a cup? In some videos it seems like we need to bleed both the caliper and the pump, while in others (like in this video), it seems like bleeding only the caliper is enough?

[@BBInfinite]

By "pump", we're assuming you mean the lever. With a hydraulic system you bleed the entire circuit at the same time. With our method, this is the case. By starting at the caliper all the air is forced out of the entire circuit at once: the caliper, the line, and the lever. These components cannot be bled separately. Some parts could be "pre bled" to get them almost there, but once assembled you'd need to bleed it again, as shown in the video, to remove all the air regardless.

[@GerhardGeficky-jg4ok]

Finally someone who knows what they are talking about about. Everybody misses this step on KZbin. Thank you Sir

[@carbonman1967]

Love how you demonstrate the importance of the right direction for the calipers in the beginning, and THANK YOU for showing how to bleed a rear brake, instead of just taking the easy way out on the front brake like most others 🙂 Great job!

[@ziickktheog609]

Great video! Love how you almost yell at us, knowing we have done wrong before.. 😄 #rehearsalwins

[@pierrebisson242]

Best and most simple explanation so far on YT. Thank you !

[@Servicevelo]

Excellent demo. I built something similar to demonstrate to customers how these units function. I also did an indexing unit to show how that works. I used Shimano Deore but the principles are all the same.

[@HenryReinosa-t2e]

I’ve only seen videos on how to bleed the front brake, I’m glad I came across this video!

[@BBInfinite]

We believe that visualization is important when bleeding brakes, and many other tasks. Once you can envision something conceptually, you are ready to get the tools out. It's not knowing the procedure. It's knowing why the procedure works.

[@NicolasCristi-i7n]

Thank u so much, this sucking air because of opening the nipple too much is exactly what has been happening in my bleedings, is what I feared.

[@smithy1011]

Omg this video explained my issue in a nutshell 😮, not tilting calliper at correct angle and using DIY bleed spacer made of cardboard which didn’t push pistons back fully

[@ciscometal]

Great explanation. A lot of mechanics should see this video.

[@MHMvanOs-qt9cc]

All the video's are far the best on KZbin. Thanks for your help !

[@zedtony8110]

The first time I've ever heard anyone mention anything about aeration. I have tried to avoid aeration but no one ever mentions it.

[@jeremydreitlein27]

What if there is no bleed port it seems I have only one screw / hole and man is it annoying to work on trying to not let air in and keep oil from getting everywhere

[@BBInfinite]

There will be a spot for the brake line, and one for the bleed/fill port. If it's not a bleed port you can hook a hose to, then yes, that's super annoying if you're forced to just catch it all with a rag. What make are these calipers you're working on?

[@TheKb117]

Planning on replacing the mineral oil in my brakes. Would you recommend a gravity bleed first to flush out the old oil, then do the caliper oil injection to bleed the air up towards the lever? My concern is that the old oil might have sediments which a gravity bleed is best to address.

[@BBInfinite]

Simply follow the method we show in the video and you can't go wrong. Once you put the bleed block in the caliper it will displace most of the fluid from the caliper. The remnants will be pushed out by the new fluid. Gravity bleeding will not work.

[@SharifiAssef-mv6gn]

Hi. I'm using the file oil what can I do thanks ❤

[@BBInfinite]

Not sure what you mean by file oil. يجب عليك استخدام السائل الهيدروليكي الصحيح

[@poxcr]

All those so called mechanics swearing by their flawless gravity bleeding "technique" should understand this!

[@BBInfinite]

The same orientation of the hydraulic components (ports up) is required for gravity bleeding to work. Gravity pulls the fluid down, but air wants to float up. We'd rather cater to the nature of things rather than fighting it, which is why we push fluid from the lowest point to chase the air up and out. We like the active approach rather than the passive, gravity approach.

[@bendardania]

What happen to the air you removed from the caliper after you rotated, you didn’t push it out…;) . Love your bb but as far as bleeding goes your method the way you demonstrated it’s terrible… unless I missed something.Also, if you look at the pistons when you have adapters installed, provided by shimano, they never fully retract. And even if they retract after the very first ride they will push out.

[@BBInfinite]

I see what you mean. He's pushing the syringe very slowly in that last bit all while he's talking. It's important not to push the fluid too fast. Air likes a gentle hand to show it to the door.

[@bendardania]

@@BBInfinite so you just not showing that part, now it makes sense. I rewatched and saw the syringe almost empty on the second shot.

[@ottalausinc709]

This is one of the best explanations of what goes on in a brake system. Have you ever played with a vacuum bleed on mtb or road brakes? This will be my next project to improve the quality of bleeds in our shop. Thanks for making this.

[@BBInfinite]

We never tried the vacuum method because we've getting first-time, no-mess results with this conventional syringe method. Please let us know if you have success with it.

[@umeyircetin9782]

Bu bilgi altın değerindedir gösterdiğin örnekteki gibi mantık aynıdır işe yarıyor.

[@stevenlevitz8895]

Gary the Science Teacher!

[@sonycarp8271]

Thanks, 🚴

[@kylehall4063]

Great tips 👌

[@NicolasCristi-i7n]

In trying to get it right I think I made my membrane in the lever leak. From the small hole, not from the screws. I tried cleaning the membrane, drying it completely but it still leaks. I bought another, but would you know if there is a typical error that may make the membrane leak?

[@Pablo_Coach]

too much pressure applied

[@HenryReinosa-t2e]

I’ve only seen videos on how to bleed the front brake, I’m glad I came across this video!

[@BBInfinite]

We believe that visualization is important when bleeding brakes, and many other tasks. Once you can envision something conceptually, you are ready to get the tools out. It's not knowing the procedure. It's knowing why the procedure works

[@greggmck1]

Why not rotate the frame in the stand so the bleed port is above the nipple to allow bubbles to exit without removing the caliper? I understand the bleed cup will not be level, but unless one floods the line with excess fluid, the bubbles will exit as the fluid is added.

[@BBInfinite]

The principle is to get the air out. If you can figure out a way to do that and it works great for you, do it.

[@sonycarp8271]

Wow, look at all the roadies, we got disc brakes, hehe, 🚴

[@BBInfinite]

😁

[@NicolasCristi-i7n]

In trying to get it right I think I made my membrane in the lever leak. From the small hole, not from the screws. I tried cleaning the membrane, drying it completely but it still leaks. I bought another, but would you know if there is a typical error that may make the membrane leak?

[@BBInfinite]

Replace the parts/membrane/seals where the leak is occurring. It's possible these parts/seals have been compromised in a way you are unaware of.

[@NicolasCristi-i7n]

I guessed that was it thank u for the video, great job! Subscribed

[@lizardmechanic8785]

If you orientate the frame in the stand correctly you dont need to remove the caliper

[@BBInfinite]

It's two bolts.

[@lizardmechanic8785]

@@BBInfinite doesn't matter if it's one, two, or ten, it's still unnecessary.

[@mahermoussallati791]

Well explained 👍

[@BBInfinite]

Thank you 🙂

[@DanTuber]

Never seen any mechanic take the caliper off the frame to do a bleed

[@BBInfinite]

...and that's a problem. The goal of bleeding is to remove every last miniscule bubble. Any amount of air equals a spongy feel that translates to improper stopping power and modulation.

[@KILLTHEREDDITOR]

Probably because your mechanics think it’s not worth their time to ensure a perfect bleed.

[@stevenlevitz8895]

“DOT fluid” would be Department of Transportation, i.e., automotive fluid.