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Rear brake problem gt250t 2010.

Discussion in 'Technical and Troubleshooting Torque' started by ben1, Jan 19, 2011.

  1. Rear brake problem gt250r 2010.

    Hi All,

    My rear brake on my 2010 hyo gt250r is not working at all! about a week ago i caught my 4 yr old son jumping off my bike, but i also noticed he was using the rear brake pedal as one of his jumping tools.... i told him not to do that and didnt think twice about it...
    anyway few days later i noticed the rear brake was sticking but it came unstuck when i took off and didnt affect the bike in anyway, but yesterday i was stopped at some lights and i used my rear brake when i stopped... i went to creep forward and noticed a fair amount of stickyness from the brake, i tried to take off and i couldnt get past 80km's, so i pulled over and the rear brake was smoking like crazy... they were stuck to the disc.. i managed to pry them appart with a flat head and headed home....

    anyway today i pulled the brake calliper off and cleaned it good.. i put it back on but the brake is not working at all, when i pump the brake there is no compression at all, just nothing... so i tried to bleed the brakes but still nothing , no fluid coming through.. i even took out the bleed valve but no fluid.

    so does anyone have any ideas what might be wwrong with it?? could the pistons be rooted from my boy jumping of the pedal??

  2. Ha. The exact same thing happened to my bro's 2010 gtr650r
    not two weeks ago.
    The master cylinder seemed to be the culprit.
    Initially his brake lever was stuck in the depressed position, after opening the bleed nipple it released, however after that no pressure was felt on the lever at
    all. Completely lax. So we assumed some internal component in the MC was stuck in the depressed position.(wish I knew the technical terms there)

    Although we tried to source a Brembo system for the bike, the solution in the end was to just buy another from Korea. I fear it will probably happen again,
    ****en hyos.
  3. still under waranty ? take it back to the shop and tell them to fix it
  4. double post removed
  5. reads like your son blew a seal in either the master cylinder or the caliper.

    It was sitting crooked at first and hence the sticky brake, but it's now blown.

  6. any way of knowing if he did in fact blow a seal? can i pull it apart to find out?
    and would it be fixable? or is a new 1 needed?

  7. If you've got no pressure at all and you can't see any leaks in the line, then it must be a seal.

    You can buy kits for the master cylinder and the calipers. these include seals and dust covers.

    Have a good look around both and look for brake fluid to give you an idea of which of the two has blown.
  8. You can't buy kits for hyo's, but SV master looks very similar...

  9. Now that is bollocks. The local distributor needs shooting.

    OK I've notice master cylinders in ebay for many bikes. International search.
  10. It's not the distributor, Hyosung don't sell the parts.
  11. Ben, you might be lucky in that the original may be just sitting askew rather than being damaged. So you may be able to pull it apart and just reassemble it.
  12. hmmm ok, thanks ibast and others for all your help...
    i will pull it apart on the weekend and see if i can find out what the go is.

    thanks again,

  13. Which end it's normally the master I've never heard of a caliper going west on a hyo yet...
  14. I thought they had fixed that problem.

    I doubt your son did any damage to it tbh. Or maybe he was just the catalyst, Hyo's Comet series have had a wonderfully reliable history of rear brake seizure. You're lucky you got on to it early. Otherwise the brakes would keep absorbing energy, and finally explode in a shower of sparks, coating the rear of the bike in whatever metal it is. Looks like it's still going strong.
  15. How did you go with the Master Cylinder...

    Mine was fully compressed aswell so i released the bleeder valve and now i have nothing.
  16. Hey Fenno,

    i Couldn't fix it, so i took it to bikebiz and the warranty covered the damage...
    they just replaced it with a new one.

  17. I just realised i still have some warranty left aswell lol... think ill take advantage of this!