Sanding brake pads made them worse?

benatbedgebury
benatbedgebury Posts: 6
in Workshop
I have shimano hydraulic discs, and decided to remove the surface of the pads with the hope of improving performance. But in fact they just skim when applied now and sound awful. They are low so will probably just replace them, but are there any tips as to why this might be and whether they can still be salvaged? Thanks

Comments

  • webboo
    webboo Posts: 6,087
    I have rims brakes but the the idea of sanding the pads down to improve performance has never occurred to me. As the idea of removing some of the braking surface to make the braking better never occurred to me.
  • wilberforce
    wilberforce Posts: 296
    After sanding them have you tried bedding them in again by a number of quick repetitive braking stops?
  • benatbedgebury
    benatbedgebury Posts: 6
    Yes, went for a ride with some intense braking, not happy bunnies
  • photonic69
    photonic69 Posts: 2,417
    I have previously used some fine 800/1000 grit wet n dry paper to resurface my pads (both disk and rim) to good effect. No problem bedding in and worked great after a couple of stops.
    You must have done something wrong. Have you repeatedly pumped the brake levers 20-30 times after refitting pads to settle them back in?


    Sometimes. Maybe. Possibly.

  • photonic69
    photonic69 Posts: 2,417
    Forgot to add - I laid the paper flat on a large smooth floor tile and rubbed the pads across it in a circular motion. Only took 3-4 seconds per pad just enough to renew the surface and leave them totally flat.


    Sometimes. Maybe. Possibly.

  • rwoofer
    rwoofer Posts: 222
    I have had the same experience and found that bedding in took far longer than when they were knew.
  • trevor.hall12
    trevor.hall12 Posts: 416
    You say they're worn ,how worn are they ?
  • MattFalle
    MattFalle Posts: 11,644
    I think by this time and with all the faffing around its time to hammer, fire, trebuchet and fit some new ones
    .
    The camera down the willy isn't anything like as bad as it sounds.
  • super_davo
    super_davo Posts: 1,140
    I do the same as Photonic when mine get cruddy and squeal as it is the only thing that seems to silence them properly. But you should use a very fine grain and only remove a tiny bit off the top where the contamination is.
    If you take too much off it is like adding several months of wear in one hit, so they'll take a while to readjust. Until then the bite point will be further on in the lever stroke and it will feel spongy.
    It is of course also possible that the problem you thought you were fixing by sanding the pads was actually air in the system, in which case, you'll probably have made things worse - the only thing to do would be to bleed the system
  • paulbnix
    paulbnix Posts: 631
    webboo said:

    I have rims brakes but the the idea of sanding the pads down to improve performance has never occurred to me. As the idea of removing some of the braking surface to make the braking better never occurred to me.

    I do remove my rim brake pads every so often as they get bits of aluminium imbedded in them. I can usually hear a different noise when braking.
    After removing the bits I sand the surface and after that I find they are quieter and have more bite.
    These are Swisstop pads if that matters.
    It doesn't seem to have an effect on how long they last as that is ages compared to disc pads.

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