How to Bleed Shimano Disc Brakes: 12-Speed Dura Ace & Ultegra

In this video, I show you how to do a brake bleed for Shimano’s new 12-speed Di2 groupset. While my bike is equipped with Dura-Ace 9270 (BR-R9270 calipers & ST-R9270 Shifters), the process is identical for Shimano Ultegra 12-speed, and is similar to the process used for Shimano’s older 11-speed models. While there are several variations of this brake bleed process that will produce similar results, the method I’m demonstrating in this video follows Shimano’s official brake bleed instructions found in their Dealer’s Manual. While I sometimes perform a simplified version of what Shimano suggests, this version is the best method of ensuring unwanted air bubbles do not get trapped in your system.
00:00 Outtake
00:30 Intro
02:32 Bike Prep
03:43 Shifter Prep
05:30 Brake Bleed
07:14 Removing Air Bubbles
10:44 Re-assembling Brake Pads
Music Credits:
Bikes by Mike Intro Scene
“5 Cents Back” by Jason Shaw on AudionautiX: audionautix.com/
Free to use as per Creative Commons Attribution 4.0 International License: creativecommons.org/licenses/...
Music unaltered
Sound Effects Credits:
Bikes by Mike First Intro Glitch
“Audio Cable Connector Noise, Glitch 3” by zapsplat.com
Free to use when crediting creator
Fast Forward Effect on First Clip
“390145__cuddlenucks__glitchy-tape.wav” by CuddleNucks at freesound.org
Licensed under CC0 1.0 (creativecommons.org/publicdom...)
Unmodified/original version
Bikes by Mike Intro Theme Song for Bouncing Wheel
“Tennis Ball Hits the Ground 01” by Sound Effects +
Standard License, Finnolia Productions Inc. House and Office, Sound Effect SFX 41802465
Bikes by Mike Intro Theme Song for Rolling Wheel
“Fishing Reel Fast” by Sound Effects +
Standard License, Finnolia Productions Inc. House and Office, Sound Effect SFX 41498102

[@holdenc1006]

Just discovered your channel and subscribed. Thanks a lot for the vid; went right into my bike maintenance playlist.

[@bikesbymike]

Thanks so much! That video needs some views 😂

[@deanwaller1029]

Thanks for this video. Going to be doing my next brake bleed myself.

[@bikesbymike]

Nice. Good luck!

[@Themilkmanskid.]

I can't see why there would be bubbles in the system after forcing fluid into the caliper and up through the brake hose. The part where you let fluid drain down into the bag doesn't seem necessary, unless bubbles get caught in the caliper and aren't forced up. I'm obviously unknowledged and still found this vid very useful. Thanks for posting!

[@bikesbymike]

I agree that’s it’s not totally necessary. Just wanted to demo Shimano’s recommended process. Maybe one time out of ten that process may be needed to remove trapped air bubbles. I spoke to a Shimano tech a couple years back that said that design of most calipers does allow for bubbles to get trapped, so the bleeding process should take this into consideration. Probably not worth the extra effort. Thanks for commenting.

[@normwachholz7221]

Great video Mike. I've been using a similar process on my mountain bike brakes. A somewhat related question is how to fix squealing disk brakes.

[@bikesbymike]

Hey Norm! I did another video on disc brake maintenance that covers that off. I find the rotors are usually the problem. Any amount of grease or grit can cause them to squeel. Here’s the link to the other video… th-cam.com/video/VbU3j3paZkM/w-d-xo.htmlsi=toyB5LgiwkDWW8dW

[@glenngoodwin3899]

Thanks for the video, Mike.
I've not done a bleed on my road bike before and am wondering about the 20° tilt .
You mentioned tilting for the rear brake as well. Can I assume you are tilting nose down again to make the lever cap opening the high point.

[@MokaBoucha]

The rear brake bleed is not quite similar (may require angling the bike differently and even removing the calliper) that’s why so many TH-camrs ONLY show the front being bled. I strongly suggest that the brake pistons be cleaned thoroughly with alcohol before inserting the pads - brake fluid can seep out the side of the pistons during the bleed.

[@bikesbymike]

Thanks. Good advice. And I agree with your point about the rear calliper being a more difficult bleed. You caught me being lazy, as that's exactly why I didn't include it in my video. I wasn't up for the extra work involved and extra camera shots ;) I sometimes remove the rear calliper to place it in a more vertical line to the brake lever, but not always. It can trap air, but not always. I'll do it only if I mess up the original bleed. Plus, I've found the most significant limiting factor in getting non-squishy brakes at the rear is the length of the brake cable line, which can't be changed.

[@MokaBoucha]

@@bikesbymike interesting point about rear brake squishiness relationship to cable length. Never thought of that but makes sense bc I’ve noticed that the rear brake lever can be more squishy than the right.