Brakes Squeaking New Bike - fix it Q?

Discussion in 'Thumpers' started by yotoma, Jul 27, 2006.

  1. yotoma

    yotoma Adventurer

    Joined:
    Jun 16, 2006
    Oddometer:
    12
    This has got me sweating bullets. Did I screw up my rear disc brake or is this something with a straight forward fix?

    Problem: Brand New '06 KTM 625 SMC. Stock counter sprocket was a 17T, so changed out to a 15T. In process had to readjust chain tension. Used chain adjusters as best I could to match left and right side equally. While there, changed basic position of foot brake pedal by adjusting push rod and stop roller. There is the recommended 3-5 mm free play on the foot pedal before piston in the brake cylinder moves.

    With bike on the lift, the rear wheel spins freely, but with a very slight brake pad rubbing for about 1/4 of the rotation. Is this okay? Don't see why only a 1/4 rotation. Should it not be rubbing at all?

    Now out on the road using the brake I get a SQUEAK!!!!. Not all the time. Not under hard braking, but seems like under easy braking as the pads start to grab. Very scary metal rubbing sound. I've got a picture to post, but don't know how.

    Question: Could this be because of mis-aligned chain adjusters? What is tolerance on getting left and right side equal?

    Could this be because of me accidently getting grease/oil/dirt/whatever on the disc or pads while working down there? If so, how to clean?

    Could this be because of imsaligned brake pads? I did pull them out of the caliper to see what they looked like. I put them back same way cause it is so easy, I think.

    HELP!! It is driving me nuts worry about screwing up the disc or other components. It should not squeak at all.

    Attached Files:

    #1
  2. Buckster

    Buckster Banned

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    Sounds like the rear rotor is warped, KTM brakes do tend to squeal a little but the fact that you are getting some rub would suggest you dinged the disc while you had the wheel off, you did not lay it on the disc did you while changing the sprocket? The wavey rotors are a bit more delicate than the round ones.
    #2
  3. yotoma

    yotoma Adventurer

    Joined:
    Jun 16, 2006
    Oddometer:
    12
    I was careful about the rotor and didn't ding or put force on it, so what is the common means to confirm that the squeak is just the regular KTM squeal you mention? Just clean the rotor with suitable cleaner and "sand" the pads a bit? I guess this could confirm if it's something else, right?
    Thanks!
    #3
  4. Willis

    Willis Don't want a pickle...

    Joined:
    Jul 21, 2005
    Oddometer:
    618
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    Patience my friend the squeal will go away. My 06 smc was the saem way the more miles you put on the less in will squeal. I'm at 2000 miles now and no squeal. They squeal at low speed or lite pedal pressure because they are metallic pads. ALL IS WELL
    #4
  5. Buckster

    Buckster Banned

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    If you can find a machine shop with an "engineers glass", you could take the rotor off and lay it on the glass to see if it is warped.
    #5
  6. yotoma

    yotoma Adventurer

    Joined:
    Jun 16, 2006
    Oddometer:
    12
    Got around to troubleshooting these squeaking brakes.

    Pulled pads and rubbed them with Scotchbrite pad and shot them clean with Brake Clean spray. Also sprayed both sides of rotor and wiped with CLEAN cotton towel. Reassembled and took it out for a spin. Tested by braking really hard and, guess what, within 4-6 times of doing this the squeak was back and actually worse!

    What can be worse?
    I did the same "servicing" to the front brake pads and rotor, and now they are squeaking too, AND making more of a rubbing sound when just rolling! :cry

    Checked freeplay adjustment of both front and back, and it is okay - - not rubbing because of plungers/calipers being engaged.

    Did my hard braking cause the pads to "glaze" any brake pad dust making the pads rub against the rotors?

    Looks like rotors got dirty with pad dust because they are not as shiny clean as after the brake clean treatment I gave them.

    Should I just go back and clean again? And then NOT test by locking them up hard during test ride?

    Since front is making bigger sound now -- rubbing/scratching, instead of plain squeaking, it makes me think that the hard braking I did made it worse. what do you think?
    #6
  7. ChrisC

    ChrisC Amal sex?

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    Feb 25, 2003
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    6,320
    Location:
    Prescott, Arizona USA Earth
    The OEM pad/rotor combination tends to be noisy, particularly at low speed application. My '03 Adventure squeaked like the hinges of hell. Put a set of EBC pads on it and it's been noiseless for 7K miles... :1drink
    #7
  8. 4SEVEN3

    4SEVEN3 Been here awhile

    Joined:
    Jul 14, 2003
    Oddometer:
    996
    Location:
    Whitsett, NC
    Brake pads will drag the rotor when on a lift and spinning by hand. Its not a huge deal. The pads stay in contact with the rotor, but there shouldnt be any real pressure. Worry about warped rotors when you have vibration/pulsating at speed and applying brakes.

    I think your perfectly fine. The compound of the brake pads, and metallurgy of the rotors may cause the squealing, but perform in a specific manner when heated up.

    Now go ride! :wink:
    #8