rear brakes

Discussion in 'Sportster Models' started by dozerman, Aug 8, 2011.

  1. dozerman

    dozerman Member

    Here we go. My first post. Had to put on new drivebelt(05 1200 custom sportster). When replacing rear caliper I manuallypushed plunger back in and long story short can't get rear brakes to work. Have tried bleeding manually at first and then got a Mity vac. Got fluid without air bubbles but still no brakes. HELP
  2. glider

    glider Veteran Member

    Possible you forced air that was in the caliper back up into the system. More bleeding may do the trick here. Check to see if you get any pressure release when you break open the bleeder screw with the brake lever depresses after a few pumps. If not you may have a master cylinder problem then. You do have brake fluid in the MC ? Right?
  3. dozerman

    dozerman Member

    Got fluid in mc reservoir. As matter of fact I vac-pumped a whole reservoir full thru the pump. So nothing but new dot 5 in there now. No pressure release when cracking open the bleeder either. Didn't expect any though cause brake pedal goes all way down without any resistance. Guess will have to rebuild mc huh?
  4. HDDon

    HDDon Experienced Member Contributor Retired Moderators

    How many times did you pump the pedal. Since you pushed the piston back in the caliper it may take several pumps to move the piston into contact with the disc.
  5. lionscar

    lionscar Member

    I had a similar issue with front brakes before, it turned out that pushing the brake piston in further than it usually travells also pushed the master cylinder through its bore further than it usually travells and this made the rubber seal come into contact with a rough spot in the bore that destroyed the seal. Bought a master cylinder rebuild kit, polished the bore with very fine wet & dry to ensure it didnt hit the same rough spot and I was back in business.

    Just re-read that and it wasnt too clear. I meant to say it pushed the master cylinder piston through its bore further than it usually travels. It did involve 2 days of repeateadly stripping and bleeding the system and a real HERES JOHNNY moment before I figured what had happened. It wont be obvious if you take the piston out, you'll only know for sure when you fit a new piston.
    Hope it goes better for you than it did for me.
    Last edited by a moderator: Aug 9, 2011
  6. jock.p

    jock.p Member

    Keep pumping,it can sometimes take quite a few before the piston moves right in.
  7. dozerman

    dozerman Member

    Got her going (or should I say stopping) again. Purchased a m/c rebuild kit, performed the necessary labor of love and now stop better than ever. Just saying thanks again. Ride safe