Shimano Dura Ace 9170 disc problems

[ODC]

Hellow everyone

Last week i picked u my brand new S-Works Tarmac SL6.
I’ve build it up with the:
- shimano dura ace di2 9170 disc groupset
- shimano dura ace c40 wheels

Now i have some problems with my brakes and rotors.
The front disc brake on my new sl6 is making a squaling noise.
If i brake hard there is no noise but a with a little bit of braking power/pressure or when i am almost staying still with the bike it makes the squaling noise.

Rear disc brake is very silent but that has an other problem. Sometimes it is sticking to the rotor.
For example if i need to brake hard before a corner after the corner you can really hear the ping ping ping noise for some time. Sometimes it helps that i brake again so that they return.

Never had these problems with my MTB wich has de Deore XT M8000
I have brake in the disc brakes like on my MTB with a lot of sprints and braking hard enough but not stopping completely
My shop said to ride for another week to see if the noise and sticking goes away (braking in enough). If it doesn’t go away then they are going to check everything.

Someone here has some ideas or solutions?

[TobinHatesYou]

Some whistling is bound to happen with the front brakes when you share roads with cars. There's just a ton of oil, rubber and other particulates. Usually dragging the front brake down a steep descent will burn most of the oil off the rotor and get rid of the slight squeal. If it persists, clean the rotor with the appropriate solvent. If you still have squeal after that, then you probably need to clean the pads too (and sand them down slightly.)

Your rear caliper is either not perfectly lined up with the rotor or your rotor isn't quite true or both.

[sharkman]

Sounds like the shop didn't do a perfect job (pads might be conterminated with brake oil)

Would also check what type of pads are fitted on your 9170 callipers. Shimano fit the LO4c metall pads with their oem callipers which are very agressive, noisy and overkill for road use the also fitted resin pads with coolant finns might be a better/quieter idea).

[moyboy]

use disc brake cleaner and clean those pads and rotors.... i bet oils / contaminates got into it.

[Kikko]

In the past 3 months since I revived my new bike with R9170 groupset, I’ve been experiencing many of the same issues as you’ve noted. Fixes have only been temporary and regular bleeding only temporarily fixes the issues.
My local bikeshop just outside Monaco had scheduled a pickup of my bike today to perform another bleed. Instead I got a call from the owner (and probably the best mechanic in the area) who told me that that he’d taken it upon himself to call Shimano to ask if they knew of known issues with dura ace hydro brakes...as my bike was an outlier in the ontext to the many high-end bikes with the same group set that he’s sold and performs regular maintenance on.
Shimano said that yes, indeed they are aware of production flaws in certain batches and would replace under guarantee after receipt of the brakes and verification!
On the one hand I’m happy we now know what the problem is and will be resolved. The bummer is that I’ll be without a bike for probably 2 weeks until new brakes are received and installed.
So, if your problems persist you should contact Shimano. Your brakes are possibly plagued with the same manufacturing defects as mine.
Good luck!

[Finx]

Check to make sure the caliper pistons are retracting fully. They can be sticky when new. There are a bunch of tutorials online (youtube, etc...) that show how to clean/lube/unstick them.

[spdntrxi]

Dirty rotors/pads or sticky calipers.

Mine make a ping ping for a second and then quiet. Tons on online tips and tricks you dont need a mechanic for.

[nycebo]

Shimano said that yes, indeed they are aware of production flaws in certain batches and would replace under guarantee after receipt of the brakes and verification!
On the one hand I’m happy we now know what the problem is and will be resolved. The bummer is that I’ll be without a bike for probably 2 weeks until new brakes are received and installed.

First, that's great news that Shimano is making good on your brakes. Second, no big deal...just ride. Stay on flats and plan your stops WELL IN ADVANCE...so you can coast to a stop.

[periodcorrect]

Kikko thanks for bringing this to light for others that are riding a 9170 group and are experiencing the same problem. Unfortunately there were numerous production runs with flawed 9170 callipers. I have no idea if Shimano has made it public but to all those experiencing this problem, contact Shimano and them replaced..

[shotgun]

Sorry to hear of the issues. I'm on the same calipers and pads but used Ashima ai2 rotors since day 1. I've never experience squealing noise. Rubbing does happen from time to time but once the rotors cool down they disappear .