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  1. #1
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    Cleaned with Isopropyl alcohol now massive squeaking...

    I have 2008 XT disk brakes which have worked flawlessly for months. The other day I decided to clean the rotors with isopropyl alcohol before a big ride. I wiped them down with a brand new clean rag (one of those Scott's rags in a box).

    I put the wheels back on and they squeaked/squealed like nothing I've heard before in my life. So I rode with the embarrassment for 25 miles and the noise never let up.

    Any ideas what I may have done wrong?

  2. #2
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    Take your pads out, sand them so they're evenly roughed up, then try again. Depending upon how thorough you've been, you may have disturbed/removed the fine layer of pad material which is deposited during the break-in period. It's also a possibility that the noise is a result of the rotors no longer being centralised due to a different torque at the QR.

    Cleaning rotors isn't really necessary unless they've been contaminated with something harmful, like brake fluid, other oils or lubricants.

    What use is a philosopher who doesn't hurt anybody's feelings? -
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  3. #3
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    I periodically clean my rotors and pads using denatured alcohol and a clean white rag. Isopropyl would be about the same. I haven't needed to sand the pads, just wipe them roughly with an clean alcohol layden white rag so I can see when they're clean. Occassionally I have sometimes had a little squeeling but it never lasts long. If I were you I'd also check to be sure caliper is centered over the rotor and aligned with it. Adjust as necessary. I'm with you though in not liking to ride a noisy bike cuz it is an embarrassment! A couple of weeks ago I had a loud obnoxious creaking sound that stayed with me on a long ride with a group. Had to do some work before the next ride. It was in the rear suspension. Good luck getting rid of your squeeling.
    Half our life is spent trying to find something to do with the time we have rushed through life trying to save

  4. #4
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    Thanks to both for the replies. I guess the first thing I'll do it re-center the calipers since that will only take a couple minutes. If that doesn't work I'll clean everything out and then hit the back of the pads with a blow torch.

  5. #5
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    "If that doesn't work I'll clean everything out and then hit the back of the pads with a blow torch."

    And what would you hope to achieve by doing that?

    What use is a philosopher who doesn't hurt anybody's feelings? -
    Diogenes


  6. #6
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    Quote Originally Posted by SteveUK
    "If that doesn't work I'll clean everything out and then hit the back of the pads with a blow torch."

    And what would you hope to achieve by doing that?
    It was my understanding that heating the brake pads to high temperature would/might boil any oil that may have been deposited on the pads. Then to lightly sand the pads after that.

  7. #7
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    It is considered a potential remedy, yes, but it is also possible that pad some pad compounds deteriorate if heated to extreme, as they may with something as severe as blow torch. Did you clean the rotors with alcohol because of an oil/lube spill? If not, I'd suggest that you simply sand the pads and get them bedded back into the rotor once you've confirmed caliper alignment. If you still get a squeal, check the pads again - oil contamination should present itself as either dark marks on the rotor or a soft-to-the-touch glaze on the pad(s).

    What use is a philosopher who doesn't hurt anybody's feelings? -
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  8. #8
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    Quote Originally Posted by SteveUK
    It is considered a potential remedy, yes, but it is also possible that pad some pad compounds deteriorate if heated to extreme, as they may with something as severe as blow torch. Did you clean the rotors with alcohol because of an oil/lube spill? If not, I'd suggest that you simply sand the pads and get them bedded back into the rotor once you've confirmed caliper alignment. If you still get a squeal, check the pads again - oil contamination should present itself as either dark marks on the rotor or a soft-to-the-touch glaze on the pad(s).
    Thank you, I will definately try your advice first before I use any heat method.

  9. #9
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    Why is this so complicated? I made the mistake of cleaning my brakes (BB7's) once.

    They squeaked.

    I went riding anyway.

    Rode through grimy mud that gummed up my brakes and made a grinding noise quite possibly worse than the squeaking, since it was persistent.

    Then I rode through sand.

    Kept on riding.

    The mud dried, and turned to dust, which fell out.

    The brakes stopped squeaking.

    Problem solved.

  10. #10
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    Make sure you are using 90+% Isopropyl Alcohol, and not using 70% (Rubbing) Isopropyl Alcohol, for cleaning. The rubbing type alcohol includes some oils for lubrication (eg. rubbing) and that's something you don't want on your rotors or pads.

  11. #11
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    That's one reason why I use denatured alcohol besides that I have it around.
    Half our life is spent trying to find something to do with the time we have rushed through life trying to save

  12. #12
    56-year-old teenager
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    I found some 100% isopropyl alcohol at a local drug store, so I use that. Or automotive brake cleaner.
    Work is the curse of the biking classes.

  13. #13
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    "Why is this so complicated?"

    It's not at all, and perhaps more a reflection upon yourself that you find it to be so. You appear to be unaware that your own experiences don't necessarily supply a Universal example.

    What use is a philosopher who doesn't hurt anybody's feelings? -
    Diogenes


  14. #14
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    Quote Originally Posted by 4slomo
    Make sure you are using 90+% Isopropyl Alcohol, and not using 70% (Rubbing) Isopropyl Alcohol, for cleaning. The rubbing type alcohol includes some oils for lubrication (eg. rubbing) and that's something you don't want on your rotors or pads.
    Who told you that?

  15. #15
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    Diomedes actually has the right cure for those that head out on the trail and have squealing brakes though you dont have to find a mud puddle. I had a Rep tell me that if I had a problem with squealing brakes to simply rub some dirt on the rotor and then ride. It does work and as far as the cleaning with alcohol... That just means you care about the bike and how it looks not just the frame but the whole bike. Clean as often as you like butbe prepaird for a little squeak until you find dirt
    Zipper aka Rob

  16. #16
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    Interesting stuff, thanks for all the replies! I haven't had time due to work/kids to look at it yet but I'll report back after I do.

  17. #17
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    Quote Originally Posted by SteveUK
    If you still get a squeal, check the pads again - oil contamination should present itself as either dark marks on the rotor or a soft-to-the-touch glaze on the pad(s).
    I have this exactly on both my rotors, a lot of them! Will the dark marks on the rotors eventually wear off? I've cleaned it and it didn't seem to come off. Hopefully I can get the pads clean enough coz my brakes are weak!!

  18. #18
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    Have you checked for fluid leaks? You've either picked something up - lube over-spray or from oily puddle in the parking lot, for example - or you're losing fluid from the caliper (piston seals or bleed nipple). You need to do some investigating to find the cause of your streaks. If it's gotten to the point of leaving gummy stains on the rotor, then there's a high probability that your pads are ruined.

    What use is a philosopher who doesn't hurt anybody's feelings? -
    Diogenes


  19. #19
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    Do NOT use Automotive Brake Cleaner!!!

    Quote Originally Posted by chucko58
    I found some 100% isopropyl alcohol at a local drug store, so I use that. Or automotive brake cleaner.
    You definitely do not want to use automotive brake cleaner on your rotors and/or pads. For whatever reason this will make your brakes very noisy! It also may deteriorate your pads very quickly. I have had Hayes, Juicys, Elixirs, and all have squeaked badly on occasion. I have tried all the remedies (heating, sanding, cleaning, realigning, beveling, new rotors, new pads...) with mixed results. What I have noticed is usually when the squeaking is getting worse, I will find that there is a glaze on the rotor. You can see lines visible in the rotor. I take them off get some 150 grit sandpaper, and sand them circularly until the glaze and the lines are gone on the rotor is shiny and clean. While I am at it I will rub the pads and rotors with some alcohol, and hit the trail. 90% of the time this has worked on both my bikes and my wife's. If that doesn't work it usually means the pads are contaminated or otherwise screwed up. I buy new pads and that has always fixed the problem. I would be very careful about what chemicals you have hitting your pads. I used to wash my bike with car soap, and found that some of the wax was getting into my pads and causing problems.

  20. #20
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    Quote Originally Posted by SteveUK
    Have you checked for fluid leaks? You've either picked something up - lube over-spray or from oily puddle in the parking lot, for example - or you're losing fluid from the caliper (piston seals or bleed nipple). You need to do some investigating to find the cause of your streaks. If it's gotten to the point of leaving gummy stains on the rotor, then there's a high probability that your pads are ruined.
    Actually, I think it was from when the machinist was test fitting the rotors when my fabricatin the 20mm centerlock lockring. His hands we're covered in some sort of machining lube. Was too excited to put it together that I forgot to clean the rotors. The stains aren't really gummy, it's more of like some parts of the rotor got burned.

    I'd hate to have to buy new pads coz my brakes are only a month old!! The question is, if the pads are contaminated, how about the rotors? Do I have to change them too?

  21. #21
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    "The question is, if the pads are contaminated, how about the rotors? Do I have to change them too?"

    Not at all. Rotors are stanless steel, so they're more or less indestructible (from a contamination point of view). No matter how much crap is on them, they can be cleaned. Take a look at this instruction for rotor cleaning. Another solution is to remove the rotor and scrub it with a scourer in hot, soapy water; just make sure to rinse it thoroughly with fresh water before refitting.

    Generally, if oily/waxy contaminates have been soaked into the pads from the heat of the braking process, they're finished. Some folks claim that heating them over flame or baking in the oven will bring them back to 'new', and perhaps in some instances it will, depending on the type of oil they've absorbed, but pad compounds are so dense that they're almost certain to hold on to some of the oil/wax.

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  22. #22
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    I like the mud/dirt solution it seems like it'll be able to take or the squeal, be prepared to have a groovy rotor though.

  23. #23
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    I'm thinking of putting my Hayes V6 rotors (came off so1e's) on my BB7. Should I clean them before putting them on the hubs?
    Mary ss shenanigans

  24. #24
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    Quote Originally Posted by helexia23
    I have 2008 XT disk brakes which have worked flawlessly for months. The other day I decided to clean the rotors with isopropyl alcohol before a big ride. I wiped them down with a brand new clean rag (one of those Scott's rags in a box).

    I put the wheels back on and they squeaked/squealed like nothing I've heard before in my life. So I rode with the embarrassment for 25 miles and the noise never let up.

    Any ideas what I may have done wrong?

    Hi - I done this w/ my brakes (front & rear). What I did to get rid of the noise was ride the breaks for about 5-10 minutes hard. It was loud, annoying, but it did go away and after using the alcohol the brakes now bite great!!

  25. #25
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    Quote Originally Posted by 4slomo
    Make sure you are using 90+% Isopropyl Alcohol, and not using 70% (Rubbing) Isopropyl Alcohol, for cleaning. The rubbing type alcohol includes some oils for lubrication (eg. rubbing) and that's something you don't want on your rotors or pads.
    I think it's astroglide.

  26. #26
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    Quote Originally Posted by john85D
    I have this exactly on both my rotors, a lot of them! Will the dark marks on the rotors eventually wear off? I've cleaned it and it didn't seem to come off. Hopefully I can get the pads clean enough coz my brakes are weak!!
    Sometimes you can save your brake pads by sanding them down past the level of the contamination.

    Sometimes they're just dead.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  27. #27
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    Quote Originally Posted by TX_Shifter
    Hi - I done this w/ my brakes (front & rear). What I did to get rid of the noise was ride the breaks for about 5-10 minutes hard. It was loud, annoying, but it did go away and after using the alcohol the brakes now bite great!!

    strange that it took that long when i use alcohol, it goes away in less than 30 seconds

  28. #28
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    Quote Originally Posted by 4slomo
    Make sure you are using 90+% Isopropyl Alcohol, and not using 70% (Rubbing) Isopropyl Alcohol, for cleaning. The rubbing type alcohol includes some oils for lubrication (eg. rubbing) and that's something you don't want on your rotors or pads.
    70% isopropyl alcohol from the drug store is exactly 70% alcohol, 30% demineralized water. The advantage to using 90 or 100% isopropyl is that it will evaporate much faster, and cut through grease easier.

  29. #29
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    Quote Originally Posted by GpzGuy
    70% isopropyl alcohol from the drug store is exactly 70% alcohol, 30% demineralized water. The advantage to using 90 or 100% isopropyl is that it will evaporate much faster, and cut through grease easier.

    Better late then never

  30. #30
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    Is there any drawback of using higher concentration such as 100% (the higher the better)? Or any advantage of using it with a percentage of distilled water?

  31. #31
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    Theoretically, lower concentration (more water) is more likely to leave a residue. I've used 70% for as long as I can remember because it's the easiest for me to get hold of.

    What use is a philosopher who doesn't hurt anybody's feelings? -
    Diogenes


  32. #32
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    I've got an annoying squeeling as well. New pads, new rotors. BB5's. I had it before I changed pads 2 days ago, and its still there. I hvent really ridden the bike in a while and it made the noise before.

    Ive read that this can be also due to an overtightened hub causing vibration through the frame (which I have when I use the back brake). Not thread jacking but I'm trying to get to the bottom of this noise as well as its so annoying.

  33. #33
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    people are all over with this thread. its called "rubbing" alcohol because iso alcohol soothes muscles to some extent. you can rub it on people. the higher percentage alcohols work better because theres more alcohol in it. water doesnt do much degreasing.. you can really use whatever, it all works. you might just find you use less 90% to get the same results, but the 70 still works fine.

    brake cleaner eats paint, plastic, rubber, skin, damn near anything. its strong as hell.. it cleans pads and rotors great, but it damages so much other crap it doesnt make sense to use on a bicycle. if you have a rotor off the bike, feel free to clean it with brake clean.. same with pads.

    i bet the heat of operation is enough to boil off most oils after a few rides. i can put enough heat into a 160mm rotor to turn it blue and smoke the pads, i cant imagine it getting that hot and not cooking out oil. brake fluid boils at ~400f.. brake rotors turn that dark purple/brown color at 800f.. about 900f turns it blue.

  34. #34
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    OK... so y'all have figured that cleaning your rotor will lead to harmonic vibration (squealing)...like a clean wine glass when rubbed on the rim

    the solution (as many noted) is something to break the micro 'grabs' which lead to more harmonics.

    My solution??
    Powdered graphite (pure - like you'd find for lubing locks)- it doesn't take much, heat resistant (your brakes wont affect it) and does the job - you can also use a pure charcoal pencil (artsy type), but I prefer the graphite - a little on a clean rag, grab rotor (with treated rag), spin and done!
    You wont have a squeal again - unless you ride through some water - you may OR may not need to reapply - I often don't.

    Uninformed/ ignorant folks, flame on
    Honestly... ahh I give up

  35. #35
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    Quote Originally Posted by highdelll
    My solution??
    Powdered graphite...
    Never heard of this one before. I like it!

  36. #36
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    Quote Originally Posted by KevinB
    Never heard of this one before. I like it!
    heh, yeah, I got ragged on for suggesting it months ago - but if you read a list of 'ingredients' for most brake pads (automotive to mtb - atleast w/ metallic), graphite is used for noise.
    I've since gotten emails/ PMs sayin' "highdelll, that worked great!" - but no one has said it publicly
    Plus, it's totally non destructive, if for some reason you didn't like it* (I don't know why) you could simply wash it away.

    *note - brakes may feel a bit slippy at first (3-4 brakings?) but not nearly as long as a new system break-in.
    Honestly... ahh I give up

  37. #37
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    For anyone with noisy brakes that have tried all the usual fixes only to still have noisy brakes. TRY THE POWDERED GRAPHITE! I got a good size container from an art supply store near my house for 8 bucks. I have been dealing with a high pitched squeaking from my Magura Louises for a long time now. After my squeaktastic ride this morning I put some on my rotors and went out in the street to test it. Noise gone. The real test will be when I go on my next ride, Wednesday night. But, it looks very promising.

    Thanks a million highdelll for posting this awesome idea!
    IT'S NOT THE FALL THAT HURTS. IT'S WHEN YOU HIT THE GROUND.

  38. #38
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    you bet man!
    thanks for the recognition
    ya may need to repeat after riding through a creek, or rinsing off the bike, but I've found that generally, there's enough left behind to 'break' the micro-grabs/ harmonics.
    Honestly... ahh I give up

  39. #39
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    i have been taking care of them just like my car and truck. i use brake clean from the auto parts store then lightly scuff the pads and rotors in a random circular motion wiith 400 or 600 grit. I stress lightly. always works for me

  40. #40
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    The only stuff I've ever cleaned my rotors with is Blue Dawn. Rinse thoroughly then ride on.
    A blind man searches in a dark room for a black hat that isn't there. Dashiell Hammett

  41. #41
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    Quote Originally Posted by highdelll
    you bet man!
    thanks for the recognition
    ya may need to repeat after riding through a creek, or rinsing off the bike, but I've found that generally, there's enough left behind to 'break' the micro-grabs/ harmonics.

    No problem, props are deserved. I'll post an update after my midweek ride.
    IT'S NOT THE FALL THAT HURTS. IT'S WHEN YOU HIT THE GROUND.

  42. #42
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    Quote Originally Posted by xcguy
    The only stuff I've ever cleaned my rotors with is Blue Dawn. Rinse thoroughly then ride on.

    Is that anything like Red Dawn? ...Wolverines!
    IT'S NOT THE FALL THAT HURTS. IT'S WHEN YOU HIT THE GROUND.

  43. #43
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    WOLVERINES!!!
    Honestly... ahh I give up

  44. #44
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    Well, I'm sold, I'll be getting that graphite today and will give my feedback later on. I've had an incessant problem, even after switching to better brakes, (BB7 203), where it squeals like and rings like a tin can doing back-flips down 5 flights of stairs. Less than my old Hayes MX2 or MX4 I forget, 160, but still. Happens at between 12pmh and 16.5 pmh, where it use to happen all the time before... so I'm thinking this might work... wish me luck.
    Be excellent to each other.

  45. #45
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    TRUST highdell!

    WORD! Squeaky rotor modulation- one day it just showed up... and stayed... I used an artsy graphic pencil (fatty) and it worked like a charm. 30 seconds and problem solved.

    Thanks to highdell!
    mountainswin
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  46. #46
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    Quote Originally Posted by mountainswin
    WORD! Squeaky rotor modulation- one day it just showed up... and stayed... I used an artsy graphic pencil (fatty) and it worked like a charm. 30 seconds and problem solved.

    Thanks to highdell!
    THX man
    I'm glad it helped...Just tryin to pass along a trick that worked for me!
    Any decrease in braking power?


    -Maybe w/ enough positive posts, It might make it to the FAQ
    vs. This and This in this Thread
    Last edited by highdelll; 08-08-2009 at 11:43 PM.
    Honestly... ahh I give up

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