Front brake lock up

Discussion in 'Wheels' started by DEP47, Jun 6, 2011.

  1. DEP47

    DEP47 Member

    I have a riding buddy with and 09 Ultra that had his front brake just come on when he was riding. Happened at a bad spot on a bridge, when he was in the left lane on a bridge. He got to the edge of the right lane and it just stopped and the clutch just slipped and then stalled. The bike has the ABS brakes and had just been int the shop for new brake pads, and tire. The bike sat a few minutes and he was able to get it off the road and the dealer picked it up.. Dealer then changed everything associated with the front brakes and gave it back, say:19:ing they could not find anything that caused the problem. Just interested if anyone else has had this occur, or what could cause this kind of a problem. This could have got the guy killed,
  2. HDDon

    HDDon Experienced Member Contributor Retired Moderators

    I'm not up on the ABS brakes but I saw this once on a friends bike. The dealer installed new pads and did not clean the pistons before pushing them back in the caliper housing. This galled the piston and caused it to stay out, pushing the new pad against the rotor. The rotor was blue from the heat and sized while going about 25mph. I think in his case the heat boiled the brake fluid.
  3. bc45

    bc45 Active Member

    It most likely had a piston stick, Then when it cooled down released, It is not common for ABS to lock up a brake.
    Was it just one caliper or both that was stuck on?
  4. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

    I would think that the piston was not correctly cleaned and pushed fully in jetting jammed holding the pad against the disk as the disc gets hotter it will eventually expand till it jams between the pads sitting still for a while the disc cools and shrinks and the bike can be moved
    as well as the brake disk the backing plate of the pads will also expand when hot

  5. DEP47

    DEP47 Member

    I thought something like that also, even though the dealer told him he could find nothing wrong. I never heard of this before but it was a very dangerous situation when it happened. Not sure what you can look for when the brakes are changed to make sure this is not a problem. Sure would not want this to happen to me. I think the dealers workmanship is probably the cause, but thought I would ask here as there is a lot of experience here.
  6. Jack Klarich

    Jack Klarich Expert Member

    Typically when brakes lock up it is caused by sticking pistons, or free travel not correct, one thing for sure with any ABS system, NEVER push old fluid back thru the system, always open a bleeder and push the fluid out, then top off and bleed. The ABS systems can not tolerate trash in the system. You may get lucky tho I have seen a lot of pumps and solenoids ruined from old fluid
  7. Breeze3at

    Breeze3at Well-Known Member

    My jaded opinion is the shop tech did something wrong on reassembly after replacing the pads. What, I can't say because I know next to nothing about ABS. The dealer is not going to tell a customer that they found something they did wrong that caused brakes to lock up. They would rather say "we replaced everything associated" and let it go.