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Hydraulic disc brakes adjustment

zoomajzoomaj Posts: 41
edited September 2017 in MTB workshop & tech
Hello guys need some help, iv got a cannondale quick x3 2014 hybrid,

It's got Cannondale Helix 6 hydraulic disc, 160 mm.

The problem I'm having is the left brake pad is a bit far away from the brake disc, and I don't know how to adjust it or bring it closer! On my previous bike there was a screw I could tighten or loosen to bring it closer or further away, but on these hydraulic disc brakes there doesn't seem to be a screw,

I'm having to press the brakes all the way in order to get some stopping power, where as the front brake I can do a 1 finger stop.

Iv taken the wheel off and pressed the brakes to bring them in the middle however only the right hand side seems to move closer, the left pad stays as it is.

I was under the impression the hydraulic disc brakes where self adjusting etc?

Iv taken the wheel off a couple of times and this seems to have happened. The wheel is definitely in the centre as I get no brake rub. Any help would be appreciated before I take it to a bike shop.

Thank you for your help and assistance in this matter

Posts

  • cooldadcooldad Posts: 32,601
    You could try lubing the piston with a bit of brake fluid - hold the one that moves and push the brakes and see if you can loosen it.

    Hydraulic brakes do self adjust, but those are proprietary brakes, so no idea of specifics.
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  • whyamiherewhyamihere Posts: 7,512
    You have a sticky piston. Take the wheel off and the pads out. Hold the right hand piston in with something like a plastic tyre lever, and then VERY CAREFULLY press the brake lever - This should force the left hand piston out. Once it's out a bit, give it a clean using isopropyl alcohol, then press it back in with the tyre lever. That should free the piston up so that they move together, though you may have to repeat the procedure a couple of times.
  • zoomajzoomaj Posts: 41
    That is super thank you il give it a try
  • zoomajzoomaj Posts: 41
    right guys quick update,

    i took the brake pads out and sorted this issue based on your advice, both pads are now moving, however i still have to press the brake lever all the way to the back, and the stopping power isnt great, i just grind to a slow halt, before it was really sharp and almost an instant stop.

    any ideas what this could be? could my brakes need bleeding?? please let me know thanks, i like to do things myself before taking it to my local bike shop.

    Thanks
  • Firstly check the pads aren't worn out (new pads would have about maybe 3mm of material on them, less than 1mm = time to replace the pads)

    Second... pop the wheel out, and leaving a small spacer in the gap where the pads would have been- something like the tip of a large flat screwdriver, squeeze the brake a few times till they bite no that. Then refit the wheel - you may need to lever the pistons apart as you've done previously, but only do it just enough to get the wheel back on, not fully shoving them back inside the caliper.

    If those don't work, then bleeding them might be worth a shot
  • zoomajzoomaj Posts: 41
    hello there

    as per instruction i took the wheel out, and then the brake pads, seems like lot of material is left on them, so i popped them back in, i then proceeded to squeeze the brakes to get them in the middle and closest the wheel as possible,
    i then put the tyre in, there was a little bit of brake rub, but then after a few squeezes they must have self adjusted
    so about 1-2mm gap between the rotor and pads, but again i have to squeeze really hard, almost all the lever is pressed before i get any stopping power, so i suspect a bleed is going to be required?

    Thanks
  • zoomajzoomaj Posts: 41
    also my cannondale is running

    Brakes Cannondale Helix 6 hydraulic disc

    where would i buy a bleed kit for this? or can i use any other, just make sure the
    Dot fluid is compatible?

    i have found this bleed kit online

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

    unless anybody can recommend another?
    can i not go into a shop and purchase something off the shelf?

    Thanks
  • cooldadcooldad Posts: 32,601
    You can, but Epic are excellent, and cheap.
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  • JBAJBA Posts: 2,790
    Zoomaj wrote:
    about 1-2mm gap between the rotor and pads, but again i have to squeeze really hard, almost all the lever is pressed before i get any stopping power, so i suspect a bleed is going to be required?

    Thanks

    Do you have to squeeze hard or is there a lot of brake lever travel before the pads start to bite?
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  • zoomajzoomaj Posts: 41
    I have to squeeze hard, even at full bite the bike fails to stop unless I press the front brakes, but the brake pads them selves are very close to the disk, I'm trying to figure out how to bleed cannondale Helix 6 hydraulic brakes, they don't seem as user friendly as shimano!
  • 02GF7402GF74 Posts: 1,294
    Zoomaj wrote:
    I have to squeeze hard, even at full bite the bike fails to stop unless I press the front brakes, o!

    Are you saying when you only use the rear brake the bike is not stopping until you use the front?
    That is pretty normal, it is the front brake that does majority of the stopping.
  • The RookieThe Rookie Posts: 27,748
    Not really, the rear brakes develop the same power, so unless the rear wheel was locked (which I'm sure he would have noticed and mentioned) there is something wrong with them, contaminated pads sounds most likely.
  • Some tips to help you adjust your brakes! You should position your bike properly and ensure it is well-lit to start adjustments. The first thing to do is to turn the caliper to the bottom and back up in one full turn. You can easily tighten the caliper bolts after you have the caliper in the right spot. The next step is to squeeze the brake lever tightly so you can center the caliper. Then, moderately tighten the caliper bolts. The next thing is to spin your bike’s wheel to test if the rotor is causing friction with the brake’s pads. Finally, align the caliper. It will be more convenient to use your hand.
  • reaperactualreaperactual Posts: 976
    edited 23 September
    Yet another obvious, random, generic post from someone with a strange long winded user name? No reply?Spam? Flag. 🚩
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