Grrr at stupid bikes

joelsim
joelsim Posts: 7,552
edited April 2014 in Workshop
Just spent an hour trying to change bloody disc pads on my bike. The bloke on YouTube did it in about a minute and a half. I have now given up as I'm going to break something, or throw the stupid damn bike out of the window.

Put the new pads on after pushing the pistons into the caliper and they just come back out again so that there is no space between the pads so I can't get the disc in. Grrr.

Comments

  • lpretro1
    lpretro1 Posts: 237
    Prob too much fluid in system. Let a little out and they will be fine
  • joelsim
    joelsim Posts: 7,552
    Fixed. By tapping a flat screwdriver in between the pads and leaving it for a few minutes, then getting the wheel nearly in position before removing the screwdriver.

    Unorthodox, and wrong, but having just taken it for a spin, all seems well!
  • crankycrank
    crankycrank Posts: 1,830
    lpretro1 wrote:
    Prob too much fluid in system. Let a little out and they will be fine
    ^^^This. And you may end up with some brake drag if you don't let out some fluid. The drag can also create plenty of heat which on a long downhill could lock up your wheel due to the expansion of the parts and no way for the pistons to retract.
  • joelsim
    joelsim Posts: 7,552
    But why would it have too much fluid in the system? None has ever been added to my knowledge since I bought it, and this was the first, albeit very overdue, brake pad change after many thousands of miles.
  • homers_double
    homers_double Posts: 8,279
    Sorry but you're all wrong, the reservoirs will compensate for pad wear, just force the pistons back into the caliper, fit new pads and bed them in.

    If they're sticking then hold one side in (used the old pad though) with a flat bladed screwdriver and pump the lever to push the opposite side out a tad. Push it back and repeat a few times.

    Do the same for the other pad as the fluid lubricates the seals.
    Advocate of disc brakes.
  • joelsim
    joelsim Posts: 7,552
    After 24 hours of sitting the pads are now completely dragging on the disc. Bike shop here I come.
  • joelsim
    joelsim Posts: 7,552
    My LBS has suggested that Avid Elixirs are known to be problematic and that I could consider swapping to Shimano XT which will be about £110 fitted.

    Worth it?
  • homers_double
    homers_double Posts: 8,279
    Avids are good brakes however they are a bastard to bleed (you need to do it in a vacume I think).

    XT's are the best brakes I've owned and even though I'm now running XTR's I still prefere the feel of the XT's.

    I'd still go with my lubricating tip, I do every time I remove any pads.
    Advocate of disc brakes.
  • joelsim
    joelsim Posts: 7,552
    OK I will try to give this a go.

    The problem I had is that initially, even though I had pushed them back in, there was no gap to get the rotor through. So I then pretty much forced them back in by hammering the screwdriver in between them.

    Took the bike for a spin and all fine and dandy. Thought it was done.

    Then the next morning, the pads are now touching the rotor on both sides again so the back wheel hardly turns.
  • napoleond
    napoleond Posts: 5,992
    Bike shop in 'advising someone to spend money' shock!
    Insta: ATEnduranceCoaching
    ABCC Cycling Coach
  • crankycrank
    crankycrank Posts: 1,830
    Brake fluid breaks down and the system can accumulate air over time which takes up more space in the lines and not leave enough room for the pistons to retract. Did your brakes have a spongy feel with the original pads or was it solid at the lever? If it wasn't solid then your system needs bleeding and fresh fluid which may solve your problem. Push the pistons all the way in before adding new fluid and make sure you have no air trapped in the lines. The piston seals also have an internal lip which retracts the piston away from the rotor when the lever is released. Sometimes these can get jostled out of place such as when installing new pads which causes the piston to not retract or may even push the piston out but can usually be re-set by just pushing the piston in all the way in without any fluid in the caliper.
  • joelsim
    joelsim Posts: 7,552
    There wasn't as much travel on the lever over the last couple of weeks for sure on the affected brake. And when removed the pads were worn down to be almost non existent.

    If I pumped the brake a couple of time then the levers seemed to be ok again and normal.
  • southdownswolf
    southdownswolf Posts: 1,525
    I started to have similar problems with my Elixir CR's, so I bled them with a kit from Epic and they seem to be fine now. Maybe worth a try for £15 instead of spending £100+ on new brakes that you really should not need.

    http://www.epicbleedsolutions.com/produ ... plete-kit/

    The hardest part was getting the piston COMPLETELY back in....

    And here is a video of how to do it...

    http://www.pinkbike.com/news/tech-tuesd ... -2010.html
    http://www.stuartmole.co.uk/
  • joelsim
    joelsim Posts: 7,552
    Funnily enough I bought one of those the other day! Going to try that first.
  • joelsim
    joelsim Posts: 7,552
    Oh well. Pistons buggered on the rear so a new set of Shimano XT.

    New brakes all round and £210 lighter of wallet.

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