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  1. #1
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    Problems with SLX brakes

    Hi all, I'm hoping someone can help me out with my brakes. I've got a set of Shimano SLX on my bike. Two problems are noise and the rear brake in particular is very very soft. I have installed new pads (Shimano brand) and bedded them in properly as well as re-aligned the calipers several times. The noise persists. As for the soft rear brake, I have bled the system a few times with no change at all. I can pull the lever almost all the way to the bars. All of my previous bikes had Juicy 7's on them and I never had these problems and I'm hoping someone can help me out.

    Thanks.

  2. #2
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    Sounds like a bad brake, take it back if you can.

  3. #3
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    Can't. Bought the bike used in early '12. I may break down and take it to the LBS to look at it. If they can't fix it I'll replace the brake set.

  4. #4
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    How did you bleed them, from the caliper back to the lever or the other way around?

  5. #5
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    I bled them like you would do automotive brakes. Depress and hold the lever, crack the bleeder, tighten the bleeder then release the lever.

  6. #6
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    Quote Originally Posted by TonyB. View Post
    I bled them like you would do automotive brakes. Depress and hold the lever, crack the bleeder, tighten the bleeder then release the lever.
    Tech Tuesday - Shimano Brake Bleed - Pinkbike

  7. #7
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    Air travels up, makes no sense to work from the lever down.

    Also. position the caliper hose and bleed nipple up.
    Detach from your frame if needed, so you are sure that al airbubbels travel up and out of the system.
    Belgian beer and Scotch whisky.

  8. #8
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    You should give us the model number of your brakes. If they are the M665s then they'll need to be bled differently than the M666s.

    When I had the M665s I was just starting to bleed my own hydraulics and I bled them twice in one "session". I went out for a long ride and after about 1 hour the lever became very soft. I had to bleed it at least two more times for it to be normal. Although the process of bleeding isn't complicated, you need to be sure you're doing it right, and I wasn't. If you've got the M666s, you'll need different parts to bleed than what is in the link from eurospek.

    As far as the noise, can you be more descriptive?

  9. #9
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    Yes bleed them from the caliper up, tons of videos on it.

  10. #10
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    I got it figured out yesterday, thanks for the replies. The problem was that I was removing the cover off of the master cylinder instead of just taking out the bleed fitting. Now they feel much better but I still can't get rid of the noise.

  11. #11
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    Your brake pads or rotor are probably contaminated. Best to replace the pads and clean the rotors with dish washing soap and alcohol.

  12. #12
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    Did that. Cleaned everything with alcohol, replaced the pads again and bedded them in. Squealing right from the get go.

  13. #13
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    are you sure you're using clean pads. They should not be squealing if you are.

  14. #14
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    Quote Originally Posted by Lemonaid View Post
    are you sure you're using clean pads. They should not be squealing if you are.
    They are brand new Shimano pads. I sanded and cleaned the rotors. I oit it all back together, align the caliper and they squeal right away.

  15. #15
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    Bought a set of resin pads and the problems went away.

  16. #16
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    Quote Originally Posted by TonyB. View Post
    Bought a set of resin pads and the problems went away.
    Did you have resin previously? While resin will provide better modulation, I've learned that running resin on my 2 sets of SLX brakes, they get overpowered and heated up on longer downhills and are completely useless in the wet. I mean zero stopping power. Took me a while to get used to running sintered pads (they break in much slower than resin) but overall much better, stronger braking and zero affect by the wet.

  17. #17
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    The bike had metal pads on it when I got it and they were noisy from day one. Replaced the pads with new metal pads, still noisy. Just replaced them with the resin last week and I haven't seen a significant decline in performance. We have a lot of stream/creek crossings so they get their fair share of water.

  18. #18
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    Quote Originally Posted by TonyB. View Post
    The bike had metal pads on it when I got it and they were noisy from day one. Replaced the pads with new metal pads, still noisy. Just replaced them with the resin last week and I haven't seen a significant decline in performance. We have a lot of stream/creek crossings so they get their fair share of water.
    Only time my metal pad shimanos make noise is when they are wet. During rainy season I actually run one metal pad and one resin pad per caliper to keep the noise down, but the power up. Works well for me.

  19. #19
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    What rotor do you have? It may be not shimano rotor. I heard avid rotor will make noise.
    my slx is always silent, with sintered or resin. My avid, is noisy in steep descent.

  20. #20
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    It takes very little to contaminate your pads and to have them squeaking. Even when installing them, if you happen to touch the pad and you have grease on your fingers, they're gonna squeak. It maybe your rotors that have some kind of grease or oil on them which could fly on from anywhere. Oily hands could do it too. Too much lube on the hub could make that lube spray up on the rotor and onto your pads. I'm never careful when removing my pads so I keep a few extra sets around.

    I use pads from BleedBicycles.com which are a great price and they work well.

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