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sticky brakes

hastingshastings Posts: 206
edited March 2008 in MTB workshop & tech
now i blew a flat (i mean blew my inner in half because of large rock) and then when i took my wheel off i accidentally stood on my front brake lever (the wheel which i had taken off) and now my pads seem to be stuck really close together and i cant seem to get them apart.

I have Shimano BR-M485 Hydraulic Disc brakes

help... :cry:

Posts

  • nicklousenicklouse Posts: 50,675 Lives Here
    push them apart again. using something clean.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • hastingshastings Posts: 206
    i tried that but it didnt seem to work
  • ginge7289ginge7289 Posts: 31
    you need to get something in between them to get them apart, the callipers just need pushing back.
  • nicklousenicklouse Posts: 50,675 Lives Here
    hastings wrote:
    i tried that but it didnt seem to work

    try again.and have a read of the manual as it will confirm this.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • hastingshastings Posts: 206
    i didn't get a manual with the bike. where can i get one from?
  • endurojcbendurojcb Posts: 170
    From here:

    http://techdocs.shimano.com/techdocs/bl ... 0094975113

    Google is a wonderful thing :!: :lol:
    2007 Merlin Malt 4
  • god1406god1406 Posts: 554
    My Avid juicy 5's have the same problem. Front and back, i've tried to reset the pistons with a screwdriver (gently), using plastic wedges, and spacing them apart with cardboard (as the manual suggests). None of these have worked, although the screwdriver method DID work on my Hayes 9's.

    is there some kind of magical 'reset button' i'm missing out on, or some way of spacing the pads apart other than the ways i've already done?
    Rocky Ridge

    Stuff
  • skylinerskyliner Posts: 613
    Drop the wheel. Open the bleed port at the lever while the bike is upright, and push the pads apart, or pistons home into the bores. (same thing) then close bleed port screw. If pistons spring back out after doing this, drop the pads, and pull the lever gently to expose the pistons more, and lube them with brake fluid, or silicione grease on a cotton bud. Push the pistons home, and refit pads & wheel. Loosen post mount bolts, and pull brake lever a few times to set pistons. Then centre rotor between pads, and tighten bolts.
    They should work perfectly.
    It's nice to be important, but it's more important to be nice.
  • endurojcbendurojcb Posts: 170
    It's always a good idea to use the plastic wedges you get with hydraulic brakes when you remove the wheels. It doesn't matter whether it's for 10 seconds or 10 minutes. Accidents happen. You'll be glad you put the wedges in if it happens again. I've done it myself before, and it is a right pain to get the pads apart without damaging the surface of them. I always use the wedges now tho!
    2007 Merlin Malt 4
  • god1406god1406 Posts: 554
    ahhhhhh censored . I may have over done it with the screwdriver, brake fluid is all over the resevoir at the lever and has been forced past the seals.

    Hooray!
    Rocky Ridge

    Stuff
  • skylinerskyliner Posts: 613
    You should get a bit of fluid out of the lever bleed port, because that's what's allowing you to fully push the pistons back home, and create space for the new pads. Lots of fluid out of there sounds like the brake will need a bleed.
    It's nice to be important, but it's more important to be nice.
  • god1406god1406 Posts: 554
    yes, but there was originally enough room for the pads, then the pistons came together and now fluid has leaked out of the master cylinder.

    I havn't changed the pads, so it seemed a bit weird that the pistons were originall further apart than they are now.

    That post made no sense. damn my sentance-constructing abilities...
    Rocky Ridge

    Stuff
  • skylinerskyliner Posts: 613
    Yes it did make sense to me, but, I fear you've pulled the brake lever again, but this time with no pads in. And now fluid has leaked out of the caliper, or "slave cylinder" from your description of events.
    it's not a big problem, you just need to split the caliper, lube and replace the pistons, and then bleed the brake.
    If you're not familiar with the process, get your Local Bike Shop to do it for you.
    It might cost you a few ££'s but it's better than no brakes.
    It's nice to be important, but it's more important to be nice.
  • god1406god1406 Posts: 554
    after a muddy ride today i've decided that I don't care...

    even after mopping up brake fluid with my cut-ridden fingers. yey toxic!
    Rocky Ridge

    Stuff
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