Go Back  Bike Forums > Bike Forums > General Cycling Discussion
Reload this Page >

help with a squeaky disk brake

Notices
General Cycling Discussion Have a cycling related question or comment that doesn't fit in one of the other specialty forums? Drop on in and post in here! When possible, please select the forum above that most fits your post!

help with a squeaky disk brake

Old 10-20-20, 03:04 PM
  #1  
benjamin163
Newbie
Thread Starter
 
Join Date: Mar 2020
Location: London
Posts: 72

Bikes: Hoy Shizuoka, Condor Acciaio

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
Liked 9 Times in 9 Posts
help with a squeaky disk brake

hello,
I just changed the fluid in my front disk brake and also changed the pads.
All is working well but the brake makes the most awful shriek when the pads engage on the disk.
It really is incredibly loud.
Is this normal for new pads? Will the noise reduce with wear? Or have I done something wrong?
All help gratefully received. Thank you.
benjamin163 is offline  
Old 10-20-20, 03:47 PM
  #2  
Elvo
Senior Member
 
Join Date: Oct 2006
Location: Orange County, CA
Posts: 4,746
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 621 Post(s)
Likes: 0
Liked 357 Times in 196 Posts
Probably failure to clean the old rotors and bed in the new pads.

https://www.bikeradar.com/advice/wor...sc-brake-pads/
Elvo is offline  
Likes For Elvo:
Old 10-20-20, 04:09 PM
  #3  
tyrion
Senior Member
 
tyrion's Avatar
 
Join Date: Oct 2015
Location: San Diego, California
Posts: 3,825

Bikes: Velo Orange Piolet

Mentioned: 27 Post(s)
Tagged: 0 Thread(s)
Quoted: 2060 Post(s)
Liked 1,666 Times in 807 Posts
Originally Posted by benjamin163 View Post
hello,
I just changed the fluid in my front disk brake and also changed the pads.
Did you bed n the new pads?

tyrion is offline  
Likes For tyrion:
Old 10-20-20, 04:29 PM
  #4  
cxwrench
Senior Member
 
cxwrench's Avatar
 
Join Date: Jul 2013
Location: Nor-Cal
Posts: 3,767

Bikes: lots

Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 1953 Post(s)
Liked 2,923 Times in 1,487 Posts
Contamination.

And of course this shouldn't be in GD, but should be posted in 'bicycle mechanics'.
cxwrench is offline  
Old 10-20-20, 05:12 PM
  #5  
Bigbus
Very Senior Member
 
Join Date: Mar 2018
Location: Always on the Run
Posts: 1,211

Bikes: Giant Quasar & Fuji Roubaix

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 413 Post(s)
Liked 342 Times in 243 Posts
What kind of pads are you using. You mention they're new, are they different than what you had before? I switched to organic resin pads and my squeals went away. You also need to bed them in and hopefully you did a thorough cleaning of the rotor before you installed them. Good luck,
Yes, this might get more hits in Bicycle Mechanics, but the heading kinda says it all.
Bigbus is offline  
Old 10-20-20, 05:58 PM
  #6  
Mulberry20
Senior Member
 
Join Date: Jun 2016
Posts: 733
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 440 Post(s)
Liked 199 Times in 136 Posts
I switched to Swiss Stop blue compound and no noise at all.
Mulberry20 is offline  
Likes For Mulberry20:
Old 10-21-20, 02:08 AM
  #7  
benjamin163
Newbie
Thread Starter
 
Join Date: Mar 2020
Location: London
Posts: 72

Bikes: Hoy Shizuoka, Condor Acciaio

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
Liked 9 Times in 9 Posts
Originally Posted by tyrion View Post
Who Knew???
Such a kerfuffle!
I did none of the 'bedding in' I'm afraid.
Another lesson learnt.
And I was so pleased with myself for finally getting the bleed done.
benjamin163 is offline  
Old 10-21-20, 02:09 AM
  #8  
benjamin163
Newbie
Thread Starter
 
Join Date: Mar 2020
Location: London
Posts: 72

Bikes: Hoy Shizuoka, Condor Acciaio

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
Liked 9 Times in 9 Posts
Ha,
I did none of the above.
I was basking in the glory of a successful brake bleed.
A job half done and all that.
I'm off out into the rain to 'bed in'.
benjamin163 is offline  
Likes For benjamin163:
Old 10-22-20, 08:58 AM
  #9  
rydabent
Senior Member
 
rydabent's Avatar
 
Join Date: Apr 2010
Location: Lincoln Ne
Posts: 9,716

Bikes: RANS Stratus TerraTrike Tour II

Mentioned: 43 Post(s)
Tagged: 0 Thread(s)
Quoted: 3113 Post(s)
Liked 959 Times in 575 Posts
Disc brake pads are sensitive to the angle they work at, just like rim brakes. A slightly wider clearance where the disc turns into the pad will stop the squeak.
rydabent is offline  
Likes For rydabent:
Old 10-22-20, 09:40 AM
  #10  
cxwrench
Senior Member
 
cxwrench's Avatar
 
Join Date: Jul 2013
Location: Nor-Cal
Posts: 3,767

Bikes: lots

Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 1953 Post(s)
Liked 2,923 Times in 1,487 Posts
Originally Posted by rydabent View Post
Disc brake pads are sensitive to the angle they work at, just like rim brakes. A slightly wider clearance where the disc turns into the pad will stop the squeak.
I'm wondering how disc brake pads can be anything other than parallel to the rotor. And how you think a 'slightly wider clearance' will stop noise caused by contamination?
cxwrench is offline  
Likes For cxwrench:
Old 10-22-20, 01:19 PM
  #11  
eshew
Junior Member
 
Join Date: Feb 2013
Posts: 97
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 33 Post(s)
Liked 41 Times in 24 Posts
As stated above, if after bedding in the new pads you're still squeaking away then you've got contaminated pads & rotors

Prior to doing anything make sure your rotor's dont say "for resin only" IF they do and you're using metallic pads, there's your problem.

Do clean the rotors as best you can, dish soap & water or rubbing alcohol. Get the pads & rotors nice & wet & try to bed in again.

If that doesn't change anything, take the pads out. Get a propane torch & torch each pad for 45 seconds. As they cool, re clean your rotor. After they cool gently sand them clean using a fresh part of sand paper for each pad.

Re bed, you should be good to go.

I've used the "torch" method more times than I remember & it saved the pads every time.
eshew is offline  
Likes For eshew:
Old 10-22-20, 01:56 PM
  #12  
Cyclist0108
Occam's Rotor
 
Join Date: Jul 2013
Posts: 7,248
Mentioned: 61 Post(s)
Tagged: 0 Thread(s)
Quoted: 2366 Post(s)
Liked 2,329 Times in 1,162 Posts
You don't have to get the pads or rotors wet to bed them in properly. Just apply one set of brakes and ride as hard as you can for 50 meters. Repeat with the other set. Then you are done.

You don't have to use a torch to clean the pads. A bit of sandpaper will work (if indeed you need anything at all, which you probably don't). Unless you got brake fluid on the pads, they are probably fine.

Clean the rotors with isopropanol or ethanol and a paper towel.

Brakes do make noise in rainy conditions sometimes.
Cyclist0108 is offline  
Old 10-22-20, 06:04 PM
  #13  
Bigbus
Very Senior Member
 
Join Date: Mar 2018
Location: Always on the Run
Posts: 1,211

Bikes: Giant Quasar & Fuji Roubaix

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 413 Post(s)
Liked 342 Times in 243 Posts
I clean my pads and rotors with Acetone (nail polish remover) and then lightly sand the pads with 240 grit paper. Bed in with water (usually from my water bottle) and many short braking stops. Do not lock them up until you've finished bedding them. I should add that I only use resin pads. Good luck,
Bigbus is offline  
Likes For Bigbus:
Old 10-22-20, 06:15 PM
  #14  
themp
Full Member
 
Join Date: Aug 2015
Location: Raleigh, NC
Posts: 278

Bikes: Specialized Crosstrail

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 101 Post(s)
Liked 46 Times in 36 Posts
One other option that I have to do every so often is to reset the caliper to the rotor. You loosen the two bolts that hold the caliper and then apply the brakes with good force. Tighten the bolts while applying the brakes. This then makes the caliper straight with the rotor.
themp is offline  
Likes For themp:
Old 10-24-20, 05:34 AM
  #15  
benjamin163
Newbie
Thread Starter
 
Join Date: Mar 2020
Location: London
Posts: 72

Bikes: Hoy Shizuoka, Condor Acciaio

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
Liked 9 Times in 9 Posts
Hello all,
I can't thank you enough for all these answers.
I widened the clearance. That didn't work with the howling noise.
I've taken out the pads and have taken a picture of them and the rotor.
It looks to me like the pads are a dirty. Would you say so?
But it also looks like the pads are only engaging on the rims of the rotor.
What seems clear to me is that the rims of the rotor are full of residue from the pads and the middle isn't.
The pads seem to back this up because the coating in the middle of them hasn't been touched whereas the outer parts of the pads have been rubbed clean.
I wonder why that is happening? Can anyone enlighten me?
In the meantime I shall take your advice and clean both the pads and the rotor and try again.
Your thoughts are hugely appreciated.
And at least I'm getting a good lesson in the finer points of disk braking systems.
Ps the noise of the brake only comes as the bike comes to a standstill. The harder I pull on the lever, the more horrible the noise. Juddery too.



benjamin163 is offline  
Old 10-24-20, 05:35 AM
  #16  
benjamin163
Newbie
Thread Starter
 
Join Date: Mar 2020
Location: London
Posts: 72

Bikes: Hoy Shizuoka, Condor Acciaio

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
Liked 9 Times in 9 Posts
Originally Posted by wgscott View Post
You don't have to get the pads or rotors wet to bed them in properly. Just apply one set of brakes and ride as hard as you can for 50 meters. Repeat with the other set. Then you are done.

You don't have to use a torch to clean the pads. A bit of sandpaper will work (if indeed you need anything at all, which you probably don't). Unless you got brake fluid on the pads, they are probably fine.

Clean the rotors with isopropanol or ethanol and a paper towel.

Brakes do make noise in rainy conditions sometimes.
I may well have been clumsy and got brake fluid on the pads. Do you think this will rub off naturally or do I need to get the sandpaper out?
I have posted pictures of the pads below. Do they look to you like they need a good sandpaper?
benjamin163 is offline  
Old 10-24-20, 08:01 AM
  #17  
rydabent
Senior Member
 
rydabent's Avatar
 
Join Date: Apr 2010
Location: Lincoln Ne
Posts: 9,716

Bikes: RANS Stratus TerraTrike Tour II

Mentioned: 43 Post(s)
Tagged: 0 Thread(s)
Quoted: 3113 Post(s)
Liked 959 Times in 575 Posts
Originally Posted by cxwrench View Post
I'm wondering how disc brake pads can be anything other than parallel to the rotor. And how you think a 'slightly wider clearance' will stop noise caused by contamination?
The caliper is mounted with two bolts. You can indeed affect the pad angle by shimming the calipers at those two bolts differently.
rydabent is offline  
Old 10-24-20, 08:37 AM
  #18  
Bigbus
Very Senior Member
 
Join Date: Mar 2018
Location: Always on the Run
Posts: 1,211

Bikes: Giant Quasar & Fuji Roubaix

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 413 Post(s)
Liked 342 Times in 243 Posts
Hey Benjamin, Looking at the pads, I would start by cleaning them with alcohol or acetone and then rub them over 240 grit sandpaper until all the glazing is gone and they look uniform again. You also need to clean the rotors with the same stuff because the oil has been transferred to them also. Do all that and make sure you use clean rags or paper towels so you don't just spread the oil around. With that done, use a little water and bed them in. Do not lock up the brakes or overheat them. Lots of easy rolling stops. As they bed in the noise will stop and the braking power will increase.
Bigbus is offline  
Likes For Bigbus:
Old 10-24-20, 09:03 AM
  #19  
cxwrench
Senior Member
 
cxwrench's Avatar
 
Join Date: Jul 2013
Location: Nor-Cal
Posts: 3,767

Bikes: lots

Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 1953 Post(s)
Liked 2,923 Times in 1,487 Posts
Originally Posted by benjamin163 View Post
I may well have been clumsy and got brake fluid on the pads. Do you think this will rub off naturally or do I need to get the sandpaper out?
I have posted pictures of the pads below. Do they look to you like they need a good sandpaper?
If you got brake fluid on your pads they are ruined. No ifs ands or buts about it, they need to be replaced. They are very porous and the fluid will get all the way through however much friction material is left.
cxwrench is offline  
Likes For cxwrench:
Old 10-24-20, 09:11 AM
  #20  
benjamin163
Newbie
Thread Starter
 
Join Date: Mar 2020
Location: London
Posts: 72

Bikes: Hoy Shizuoka, Condor Acciaio

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
Liked 9 Times in 9 Posts
Originally Posted by Bigbus View Post
Hey Benjamin, Looking at the pads, I would start by cleaning them with alcohol or acetone and then rub them over 240 grit sandpaper until all the glazing is gone and they look uniform again. You also need to clean the rotors with the same stuff because the oil has been transferred to them also. Do all that and make sure you use clean rags or paper towels so you don't just spread the oil around. With that done, use a little water and bed them in. Do not lock up the brakes or overheat them. Lots of easy rolling stops. As they bed in the noise will stop and the braking power will increase.
Thanks for this. Everthing you suggested has been done and guess what? No more gut wrenching sounds!!! Thanks so much for your help and advice.
benjamin163 is offline  
Likes For benjamin163:
Old 10-24-20, 09:15 AM
  #21  
benjamin163
Newbie
Thread Starter
 
Join Date: Mar 2020
Location: London
Posts: 72

Bikes: Hoy Shizuoka, Condor Acciaio

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
Liked 9 Times in 9 Posts
Just to say, thank you everyone for the advice.
A good clean of the pads and the disk has done the trick.
I never would have thought a little dirt could make such an outrageous noise.
Thanks again.
benjamin163 is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell or Share My Personal Information -

Copyright © 2023 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.