Giant MP3 brakes

sicknewt
sicknewt Posts: 181
edited April 2008 in MTB workshop & tech
Hi all,

I suspect I already know the answer to this, but here goes...

I've got a 2007 Xtc 3.5 which I'm really happy with apart from the brakes. I keep having to add/remove washers to the brake mounts to keep the discs centred properly and I'm getting board of doing it!

Am I missing something in the set-up or are these brakes just a bit rubbish?

Unless I can figure this out the brakes are defenitely the first thing that will be upgrated!

Ta,

Nick.

Comments

  • supersonic
    supersonic Posts: 82,708
    When you put the wheel back in, it has to be the same as before - with the same QR tension. Also check the caliper isnt slipping, and the pistons are not sticking. I think its set up, not the brake.

    The brake is a 'closed' system hence they dont self adjust. As the pads wear, use the dial to bring them in closer.
  • S_J_P
    S_J_P Posts: 908
    I actually quite like the MPH3 brakes! :?

    When I first had my bike, I had to reset the calipers three times as I suffered horrendous mis-centering whenever I removed the wheels. After setting them up properly, using a variety of techniques (white-card, prying the pistons back, pulling the lever with the mounting bolts loose, etc.) I finally hit the sweet spot and they've been fine for a year, even after a pad change.

    Persevere with them, they're not that bad! 8)
  • sicknewt
    sicknewt Posts: 181
    Cheers for the answers!

    1. How do I check if the caliper is slipping or if the pistons are sticking - and how would I fix these?

    2. Whats an easy way to get the same QR tension after removing a wheel?
  • supersonic
    supersonic Posts: 82,708
    1) Make sure the bolts are torqued correctly

    2) Do it the same as before! When closing the lever, you should start to feel resistance as it gets to 90 degrees. Adjust the nut until you do, then shut firm.
  • S_J_P
    S_J_P Posts: 908
    Removing the wheel, removing the pads, winding the brake adjusters all the way out, removing the reservoir bleed nipple, and pressing the pistons all the way back ionto their housing using a tyre-lever of large flat-bladed screwdriver should ensure that the pistons aren't sticking. Remember to use a rag to catch any overspill! Then just replace the pads and wind the adjuter back in a bit. If you're doing this, it's worth squirting a little oil onto the screw adjuster thread inside the recservoir body, as MPH brakes adjusters do tend to seize over time.

    Locktite 243 on the caliper threads prevents them coming loose once they're torqued up too.

    You could also check the axle cones aren't coming loose. On my Formula hubs, if I've been heavy handed when replacing the wheel I often find that there is too much play on the front hub in particular which throws the disc off centre. A quick adjust of the cone soon sorts that out.