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Overhauling Squeaky Hydraulics

6K views 85 replies 19 participants last post by  Lombard 
#1 · (Edited)
Hello guys, I'm wondering if you could help me.

I am in the process of overhauling my permanently squealing hydraulic brakes, apart from the levers (RS505). That includes the rotors, pads, the calipers and even the hose.

Old setup:
- Caliper: RS785
- Hose: BH59

New system:
- Caliper: R8070
- Hose: BH90

I have internal cables, so am probably going to use something like: https://www.youtube.com/watch?v=QZaGL83RMFI (with e.g.: https://www.parktool.com/product/internal-cable-routing-kit-ir-1-2)

According to the Shimano Compatibility Chart: 2018-2019 SHIMANO Product Information Web and this thread: Heads up for new Ultegra users - Weight Weenies, ST-RS505/R8070 should work just fine using a BH90 straight-straight kit.

My questions:
1) Does a BH90-SB/-SBS kit imply BH90-SS (+extra parts)?
2) Is there anything else I should be aware of?
 
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#2 ·
Forgot to mention, I've replaced both the pads and rotors before, rebled the system a couple of times, and the squeak keeps coming back again and again (dirt layer on top of pads), so I can only assume it's the calipers.


The hose change (BH59 -> BH90) is only because the new calipers (R8070) depend on it.
 
#4 ·
Looking at your previous posts on this topic, may I suggest you step away from the tools and take your poor bike to a good reputable bike shop to have this problem repaired?

I know you like to play with tools, but unless you enjoy endless frustration or just like to troll, a bike shop will be a much better route for you.
 
#18 ·
They are 'supposed to be' quieter but they don't stop as well IMHO, I wouldn't use them. He should be able to get the bike to not squeal with the J04c pads.
 
#11 ·
They came originally with the bike, but became contaminated to the point of ditching them.

I doubt it's the pads, if a fresh new pair of J04C gets constantly contaminated as well. Can't really be the rotors, as I have two pairs of those as well.

So.. I would rather get the R8070. But certainly with another go of resin pads. They were virtually silent initially.

:thumbsup:
 
#12 ·
If pads are getting contaminated....then something is wrong in your current install.

It is like having a flat tire, so going shopping for a new set of wheels.
 
#15 ·
Do you want to spend $150USD+shipping on parts and $$ or hours on labor/install...for something that could be as simple/stupid as a $0.05USD leaky o-ring? What if you spend all the money...and you have the same symptoms? Then you've not only not properly diagnosed a problem...you've spent lots of money and time to not remedy it. You're jumping from not knowing what the problem actually is--to "solutions" that you don't know the problem of.


That was and is our point and the point of any and all analogies/metaphors/comparisons etc.
 
#17 ·
Well...you already have failed at fixing the problem...and now you're simply throwing money at it hoping it fixes it.

Emphasis added:

Do you want to spend $150USD+shipping on parts and $$ or hours on labor/install...for something that could be as simple/stupid as a $0.05USD leaky o-ring? What if you spend all the money...and you have the same symptoms? Then you've not only not properly diagnosed a problem...you've spent lots of money and time to not remedy it. You're jumping from not knowing what the problem actually is--to "solutions" that you don't know the problem of.


That was and is our point and the point of any and all analogies/metaphors/comparisons etc.

Go forth and stimulate the economy. It is indeed your money. And next week after installing new hardware, and still having the same issues, you'll get a helping of "We Told You So"s.


We try to be a bit responsible and get people to do things cheaply and in the last time/effort...than resorting to throwing money blindly at the problem, and hoping something sticks.
 
#24 ·
Generally once a pad is contaminated w/ any kind of oil it's done. Sanding won't help, the pads need to be replaced. The rotors need to be absolutely spotless. You need to make sure there isn't any remaining contaminant anywhere near the rear wheel.

How do you lubricate your chain and with what?
 
#25 ·
Pre-clean the rotors with rubbing alochol.

then, try sanding the pads a bit on a flat surface and after that wash the pads by scrubbing them together against each other with some dawn soap.

If that doesn't work then try to heat the pads real good with a plumbers torch, then after they cool do the dawn soap washing again.

If that doesn't work then buy some new pads.

Of course, make sure nothing is leaking onto the pads before you do any of this.

And handle them with care after procedures are complete.

If you are washing your bicycle and using some type of detergent, reconsider this method.


good luck
 
#26 ·
I know lots of guys recommend trying to 'melt' or burn contaminants out of pads. I don't. I don't think it does any good to clean them either, but it can't hurt to try. Mostly likely you'll be replacing them. Obviously don't touch the friction material or the braking surface of the rotor w/ your bare skin, the oils will contaminate the pads/rotors.
 
#31 ·
here are my thougts:

If the pads are contaminated to the point that there is a loss in braking power, then pads are toast. Throw away. I have tried to soak contaminated pads in acetone overnight, sometimes this remove the contaminants, sometimes not. Rubbing alcohol is just weak sauce and can only remove light and superficial contaminants.

If pads are organic resin, you don't want to use the burning method as burning can change the nature of the properties of the pads themselves. Not good. Only try burning on semi-metallic pads.

Maybe the 2 halves of the calipers don't bind equally. Sticky pistons maybe? Re-shim caliper? If those don't work, rebuild caliper then.

Larger diameter rotors tend to give out more squeals because larger rotors flex more than smaller rotors. (On the other hand, larger rotors also dissipate heat better than smaller ones).

On my MTB bike, there has never been a time when I can come close to using up the life of the pads before they start to squeal for whatever reason. And like you I've tried everything from replacing hose, pads, rotor, re-shim caliper, rebuild caliper, that's pretty much replacing everything except the caliper itself. But this is livable on an mtb because brake noise is just accepted as a part of life there. On road bikes, not so much
 
#38 · (Edited)
But this is livable on an mtb because brake noise is just accepted as a part of life there. On road bikes, not so much
This line is completely false. The few times I had noisy brakes on my mtb I just about drove myself crazy trying to fix it. It is extremely uncommon for me to come across other mtbers with noisy brakes. It ruins the enjoyment of being out in the woods for everyone within ear shot. On a road people are used to car noise anyway so while squeal might bother you, it isn't bothering everyone else quite as much.

I haven't had brake squeal on my mtb in years but I've found that some combinations of caliper, pad, rotor and bike frame are just prone to squealing even if the system is perfectly clean using new pads with the brake caliper aligned perfectly. I had brakes that squealed on one bike and didn't on another simply because the frame had a different resonant frequency. I also had brake systems that squealed on every bike and I've had just brake discs that squealed on any bike with any brake system.

Being around the mountain bike community I can tell you most of the time it's the discs themselves and semi-metallic pads that are the major contributors. Try switching to resin unless you actually need the extra braking power. If that doesn't work find rotors that other people have had quiet operation with. Seems like Sram Centerline rotors have been consistently quiet for road cycling. In any case if your brakes are wet they will squeal.

Just bought a new road bike with R8070 group set. Zero squealing what so ever and the braking is excellent.
 
#43 · (Edited)
#51 · (Edited)
So, unimaginably, a quick test of 1/5th the price resin pads instead of finned sintered ones completely muted the brakes (exact same method of bedding in - brake firmly from good speed without locking wheels about 10-15 times).

However, one of the pistons in the other caliper doesn't move at even speeds even after cleaning and bleeding, which keeps bending the rotor. They don't sell those separately, so gonna have to replace the whole caliper.

Otherwise, everything's nice apart from few things nothing to do with brakes. Completely fixable as well tho.

:thumbsup:
 
#52 ·
I'd spend some time trying to get the pistons to move evenly before buying a new caliper. Pull the pads out and get some mineral oil. Carefully pump the lever a couple of times to expose some of the piston and apply a few drops of mineral oil to the piston. Push it back into the caliper. Repeat as necessary. Use a plastic tire lever to push the piston to avoid damaging it. When you get them moving the same clean up w/ isopropyl.
 
#54 ·
Are you guys saying most all "hydraulic" brake systems on the market will 'squeal" like this if you don't regularly maintain them? I mean, ole'd rim pads are plug and forget for something like 10k miles.

How often is this "cleaning" and "adjusting" of them going on?

My skepticism of "hydraulic" brakes might turn into outright hatred if you guys say this has to be performed fairly often. The only disc brakes I heard squeal were the very early versions, that were not 'hydraulic', and the squeal only happened when they either sprinted and/or braked.

Thus I thought the "hydraulic" and "direct-mounted" brakes removed all this worry....???? :confused:
 
#56 · (Edited)
Not sure you read the thread.

For my permantently squealing brakes the fix was 6€ resin pads. The pistons moving unevenly, not sure, will have to see, but havent really heard of "most all" hydraulics acting like this. Certainly plenty more than rims (less tolerance), but people with no issues rarely create threads about it. Maybe a few "never had any problems" or "haven't touched them apart from changing pads for 3 years" here and there.

But if you want to "hate" them, go ahead, it's a free world. :D
 
#62 ·
Oh dear, I'm out of popcorn. :cryin:
 
#77 ·
This discussion reminds me of discussions I heard when personal computers were still young. Somebody had a problem with DOS 2.3. and the reactions were predictable. There always was the equivalent of “For my permanently squealing brakes the fix was 6€ resin pads.”

(What are you complaining about? The solution is simple! If only you knew what you were doing, man. DOS 2.3. is fine, a huge improvement over DOS 2.1.! If you don’t see that, you’re the problem! You don’t want to go back to mechanical typewriters, do you, dumbo luddite?)

Not saying personal computers were a bad idea. In the end, even Microsoft programmed a decent operating system. Just saying that for an independent observer, these discussions create the impression that it pays to wait until the issues are ironed out.
 
#78 ·
This discussion reminds me of discussions I heard when personal computers were still young. Somebody had a problem with DOS 2.3. and the reactions were predictable. There always was the equivalent of “For my permanently squealing brakes the fix was 6€ resin pads.”

(What are you complaining about? The solution is simple! If only you knew what you were doing, man. DOS 2.3. is fine, a huge improvement over DOS 2.1.! If you don’t see that, you’re the problem! You don’t want to go back to mechanical typewriters, do you, dumbo luddite?)

Not saying personal computers were a bad idea. In the end, even Microsoft programmed a decent operating system. Just saying that for an independent observer, these discussions create the impression that it pays to wait until the issues are ironed out.
The issues ARE ironed out. We've been running them on mtb bikes for years. The problem is the crowd that have only recently started using them on road bikes with no previous experience.

There really is no reason to wait at this point, other than them being as un-needed as T!t$ on a Bull!
 
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