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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.
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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?
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  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).
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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
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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.
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  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
    Zipper
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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.
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  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.

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