Brakes squeaking

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  • 11-10-2012
    addATX
    Brakes squeaking
    Hi,
    Can anyone explain how to eliminate a disc brake squeaking?

    There are probably 20 threads about it, but it just got really overwhelming trying to look through them...

    I have 2012 Shimano XT brakes, and my front one is squealing every time I use it.

    Should I clean it with something?
  • 11-10-2012
    MTBerNick
    Are you losing your braking performance? Does it happen after lots of use?
  • 11-10-2012
    addATX
    No, not losing performance - it works fine.

    It happens throughout the entire ride. Starting from house (w/ cold brakes), all the way til the end.
  • 11-10-2012
    MTBerNick
    Are the pads new or old? My new pads squealed like a stuck pig for the first 2 rides. If its not effecting performance, I wouldnt worry about it....although squeaky/squealling brakes are annoying.
  • 11-10-2012
    deke505
    have you tried to readjust them?
  • 11-10-2012
    addATX
    About 7 months of use right now.

    (Yes, really loud and annoying).

    I've had to adjust them a little from the part on the handlebar. But, I haven't messed with them on the caliper or pads.
  • 11-10-2012
    shibiwan
    Try this quick preliminary procedure to re-align your calipers to the disc. It probably won't help squealing but who knows it may.

    1. Slightly loosen the two Torx screws (T25 size) holding the brake caliper to the post mount or mounting adaptor. Make sure the brake caliper can jiggle around freely once the screws are loosened.

    2. Spin the wheel by hand (the noise would seem to be louder at this time).

    3. While the wheel is spinning, squeeze the brake lever firmly and stop the wheel. Do not let go yet.

    4. Holding on to the brake lever, tighten up the two caliper mounting screws. You can let go of the lever after the mounting screws are tightened.

    5. Spin the wheel again - the noise will be reduced somewhat.

    If the noise is reduced except for one spot, then you need to true the brake disc.
  • 11-10-2012
    sauprankul
    Some say some kind of copper grease behind the pads stops squeaking (look it up). Try sanding the pads. Are the rotors clean (with rubbing alcohol)?
    If nothing else works, get organic pads.
    Oh yeah, after you sand your pads or get new ones, break them in (look it up).
  • 11-16-2012
    CSC
    Quote:

    Originally Posted by sauprankul View Post
    Some say some kind of copper grease behind the pads stops squeaking (look it up). Try sanding the pads. Are the rotors clean (with rubbing alcohol)?
    If nothing else works, get organic pads.
    Oh yeah, after you sand your pads or get new ones, break them in (look it up).

    Organic may squeak less, but they don't work as well in certain environments...like dust.

    I'd re-center the caliper, then do some really hard braking...you may have crystallized material on the surface of the pads from the pads heating up then cooling too fast. Get up some speed, hit the breaks, and repeat with decreasing force, so that the pads cool slowly. This will have the same effect as sanding the pads w/o risking uneven sanding patterns.

    Clean the rotors with a clean, damp cloth...just wipe to remove dust.

    Grease and brake pads sounds like some sort of sick prank :p

    7 months sounds like a warped rotor and an off-center caliper.

    EDIT: start with the hard braking cycles. then clean the rotors, then start messing with the calipers
  • 11-16-2012
    jpatt28
    Squeal out works wonders for me
  • 11-16-2012
    wschruba
    CRC Brake Quiet. Comes in a can, tube, or bottle. Pick it up at your local auto parts store, remove your pads, place them braking side down, and hit the backs of the pads. Let it set for 10-15 minutes, then reinstall them into your calipers.

    Assuming your brakes are properly installed, this should take care of the noise.
  • 11-16-2012
    50calray
    My brakes on my KHS would stop on a dime but would wake the dead. A quick change in pads fixed everything. I'm not sure if changing the pads will help in your case but it' orth a shot.
  • 11-16-2012
    sauprankul
    Quote:

    Originally Posted by wschruba View Post
    CRC Brake Quiet. Comes in a can, tube, or bottle. Pick it up at your local auto parts store, remove your pads, place them braking side down, and hit the backs of the pads. Let it set for 10-15 minutes, then reinstall them into your calipers.

    Assuming your brakes are properly installed, this should take care of the noise.

    I think this is what I meant by grease. Its some kind of film forming substance that dampens vibrations.
  • 11-16-2012
    wschruba
    Yes, it has a grease-like consistency, but sets up to a tacky, rubbery feel.

    It is the best money you can spend on squealing brakes, as at $7 a can, it is handily a little more than an eighth the price of a set of different pads.
  • 11-17-2012
    yoelmtb
    may be they got lubricant, if that is the case just clean them with alcohol!!
  • 11-17-2012
    wmac
    Yes, clean the rotors. Then, take your pads out and rotate them 180 degrees so the inside pad is now the outside pad and outside is now inside. Then follow these steps: Workshop: How To Bed In Disc Brake Pads - BikeRadar
  • 11-17-2012
    sauprankul
    Quote:

    Originally Posted by yoelmtb View Post
    may be they got lubricant, if that is the case just clean them with alcohol!!

    If you got anything more than a small fingerprint on the rotors, chances are the pass are contaminated. The lubricant will usually diffuse through the pad if it is serious enough. Time to replace. If not too serious, try and sand.

    Also, check the tightness of EVERYTHING in front, including headset, brake mounts and adapters, wheel bearings and QR/TA.
  • 11-18-2012
    kjlued
    Motor oil on the rotor......j/k;)

    I have been told to pull the pads and scuff them with sandpaper and clean the rotors.
    I am just too lazy to try it.

    Only my rear squeals anyways and since I use the rear too much anyways, I use it as a reminder to use the front more.
  • 11-18-2012
    sauprankul
    The rear brake should be used as a drag brake when controlling your speed down descents. That way, when it does overheat, you still have your front brake available. At least, that's what I think. :confused:
    Anyway, if the brake you're supposed to drag for a long time is squealing... :eekster:

    EDIT: Have you tried switching you levers? I heard some newer brakes have that reversibility.:thumbsup:
  • 11-18-2012
    osokolo
    Quote:

    Originally Posted by yoelmtb View Post
    may be they got lubricant, if that is the case just clean them with alcohol!!

    the first thing i would try is re-alling the caliper - procedure explained in this thread.

    if realignment doesn't fix it - replace the brake pads. after bedding them in - if the squeal is gone - good.

    if not - then it is not the brake pads, obviously - next step is to clean the rotor with alcohol, removing any residue on it.

    if this doesnt fix the problem - i'd try another brand of brake pads.

    it also may help if you have a spare rotor - which i would replace as well - in order to eliminate each component as a source of the problem.
  • 11-18-2012
    CSC
    Quote:

    Originally Posted by sauprankul View Post
    The rear brake should be used as a drag brake when controlling your speed down descents. That way, when it does overheat, you still have your front brake available. At least, that's what I think. :confused:
    Anyway, if the brake you're supposed to drag for a long time is squealing... :eekster:

    EDIT: Have you tried switching you levers? I heard some newer brakes have that reversibility.:thumbsup:

    You should not use either brake as a drag brake, because overheating of the pad causes the surface material to change it's chemical structure, and the new, burnt material is what squeals.

    Again, easiest thing to do would be a few hard stops and a bit of trail braking to cool the pads slowly to shave off the burnt material. Or sand the pads.
  • 11-18-2012
    CSC
    Quote:

    Originally Posted by osokolo View Post
    the first thing i would try is re-alling the caliper - procedure explained in this thread.

    if realignment doesn't fix it - replace the brake pads. after bedding them in - if the squeal is gone - good.

    if not - then it is not the brake pads, obviously - next step is to clean the rotor with alcohol, removing any residue on it.

    if this doesnt fix the problem - i'd try another brand of brake pads.

    it also may help if you have a spare rotor - which i would replace as well - in order to eliminate each component as a source of the problem.

    Why not suggest doing the free stuff first? Like clean the rotor? I'd make sure all bolts are properly tightened before I start re-arranging my bike.

    I would suggest always owning a spare rotor, though...I bent mine beyond repair, and it was easy to just swap it out, rather than wait 5 days for a bike shop to order one in.
  • 11-24-2012
    Bataivah
    Probably the rotor or pads are glazed and a sanding may work. If with your braking style you re-glaze
    them you'll be back to the squeelin again. Also some brakes work better with a slight flex in the rotor
    when applied (VERY slight). That may also help a bit too.