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  1. #1
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    Disc brake grease

    I recently picked up a packet of disc brake grease from my local auto parts store thinking I could eliminate the squeal from my Hayes Mag brakes (8" rotors on Session 10).

    Does this work on mountain bike disc brakes & if so where do I put the grease? I assume, not on the braking surface as that would cause a close encounter with a rock or tree, but I may be wrong...

    Thanks!

  2. #2
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    That grease is for such things as sliding pins on floating AUTOMOTIVE pistons. Depending on what it is, it could be used for pistons, but some have to be careful because some of those greases, even for pins, are not the kind safe with DOT systems and used for pins ONLY.

    You do not need this grease on an MTB brake. If you want to lube a piston, you use a few drops of brake fluid, whatever type it is.

  3. #3
    ~Disc~Golf~
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    Don't use it!! (if anything it would go on the back side of the pads- but the likelihood of migration is too great)
    The squealing (99.9% sure) is not coming from the back-side of your pads.
    Squealing (harmonic vibration) is because of; improperly aligned calipers/ pads, brakes not broken in yet, rotor 'too' clean', rotor/ pads contaminated or when wet.
    Remedy one of these conditions to eliminate the squeal.
    how old are your brakes?
    Honestly... ahh I give up

  4. #4
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    Brakes are 3 years old. Lever modulation is fine & fluid is fine also. Brake pads (EBC red) are a few months old & have 70% left on them at least, maybe more. I generally take the brakes apart, sand the pads lightly & clean them with iso alcohol. I also scotch brite the rotors a little. This works for a while, but the noise always returns eventually.

    Could it be that the rotors heat up & distort a little putting the alignment out?

    I ride hot, dry conditions in So Cal.

  5. #5
    ~Disc~Golf~
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    did you get squeal with your old pads?
    possibly try some sintered pads?
    Honestly... ahh I give up

  6. #6
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    Old pads were stock Hayes & were like a stuck pig. Current EBC reds are better, but 15-20 mins into a DH run they squeal, but lower in pitch, more like a howl or a goose honk. I try to brake less & in shorter spurts, but switch backs need more braking for obvious reasons...

    The plus sise is the guy in front knows when I'm about to pass him & on which side!

  7. #7
    ~Disc~Golf~
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    Quote Originally Posted by AdamD79
    Old pads were stock Hayes & were like a stuck pig. Current EBC reds are better, but 15-20 mins into a DH run they squeal, but lower in pitch, more like a howl or a goose honk. I try to brake less & in shorter spurts, but switch backs need more braking for obvious reasons...

    The plus sise is the guy in front knows when I'm about to pass him & on which side!
    I don't know what the stock pads are for hayes (are they sintered or organic?)
    But, It sounds like you're gettin the brakes really hot - I don't know the 'scientific' reason why, but brakes (other objects too) will do that with extreme heat - think metals with no lube - molecular bonding? I have no clue.
    You could try what I've suggested a while back and got flamed tremendously for (so I don't suggest it much - luckily a couple guys have come to my defense, but I digress).
    Graphite...That's right, the stuff you'd use to lube things like locks and stuff. On the surface it may look like a bad idea - lubing your brakes, but at high temps graphite wont break down easily and 'lubricates' surfaces and reduces harmonic vibrations in brakes ( again I'm not a scientist, but still am fairly bright and can 'get' the concept, but cant explain it - if that makes any sense).
    You might also try a 'pure' charcoal pencil ( make sure there is no wax ) and scribble all over the rotors.
    If you're in doubt, check out the composition of many brake pads. You'll see graphite (a carbon) is used for it's quieting/ anti-squealing properties. Also, if for some reason you use too much (easy to do) or the results are unsatisfactory, it is removed easily...

    What I did on my brakes (BB7 w/ roundagons)... I put a tiny bit into a napkin (actually a coffee filter) and worked it into the rotor - the micro-scratches fill up with the graphite, then did a 'break-in'. At first, it's a bit slippy (2-3 hard stops), but not as much as a brand new set of pads (mine had been broken-in). Then it gripped as good as before, but without the squeal after a long descent. The brakes still squeal as soon as they get wet - I know of nothing that gets rid of that (likewise a 'too clean' rotor' - similar to a wet finger on a crystal wine glass). I think you need a little bit of 'dirt' to 'lube'.

    Man, I hope I'm making sense...

    Flame on Y'all

    **Disclaimer** - I have not done this on Organics...but I see no reason not to try it - try at your own peril - as I said, this 'treatment' is easily reversed as graphite wont 'soak' into pads
    Honestly... ahh I give up

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