94 FLSTN Front Brake Frustration

Discussion in 'Wheels' started by Beckysan, Aug 15, 2011.

  1. Beckysan

    Beckysan Member

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    I need help!! (nothing new there hehehe)

    About three weeks ago I had my front brake lock up on me, because the master cylinder was needing to be replaced. I rebuilt that, put in new brake fluid, but couldn't ever really get the brake lever to loosen up. I could touch the lever and I was braking. Being a newbie, I thought that maybe it just needed some bleeding and running. It does get a little better here and there, but never got to where it should be. Today I was out tooling around and had the issue happen again, where my brake lever locked and my brakes locked up too. I couldn't pull the lever and it seems like the front brake is compressing on it's own. I can pull over, I can sit for about 10 minutes, then it unlocks, I get home to the garage (using only rear brake) and it starts to lock again.

    Is it:
    A-The Master Cylinder
    B-the brake/caliper
    C-fluid
    D-All of the above

    Since I have had this bike for 2 months, I have also noticed that when I just move the bike (not running) it seems like the brake is sticky. Any help, any pointers you guys can give me would be greatly appreciated. Thank you in advance!
     
  2. R. Lewis

    R. Lewis Senior Member Retired Moderators

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    JMO here but it sounds more like the plunger down on the caliper not releasing than the MC. What DOT brake fluid did you put back in it?
     
  3. Beckysan

    Beckysan Member

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    I went by the manual and they suggested DOT 5.

    I also noticed that the reaction pin on my brake lever I can pop that up and down....(1/64" maybe) is that normal?
     
  4. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

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    From your description of the problem it seems to me that the front calliper is a wee bit sticky with the pads always touching the disc
    after a wee while the disc will get hot expand and lock up when you leave it to cool down the disc will contract and you will be able to move again
    strip and inspect the calliper ensure the pads are fitted correctly and the piston will move in and out without sticking
    the floating pad should sit in a frame with a spring clip on the top holding it in the correct location

    Brian
     
  5. Jack Klarich

    Jack Klarich Expert Member

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    If the Master cylinder is holding pressure on the calipers( lost its free travel) if you crack the bleeder on the caliper and fluid gushes out replace the master cylinder
     
  6. R. Lewis

    R. Lewis Senior Member Retired Moderators

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    Great point !!!!! :cheers
     
  7. Beckysan

    Beckysan Member

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    I will be taking a look this afternoon and let you guys know. Thanks for the feedback!
     
  8. vaughank

    vaughank New Member

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    could it be a bad plunger return spring
     
  9. Beckysan

    Beckysan Member

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    Ok...Update:
    I cracked the bleeder as you suggested Jack...No fluid.
    I have a rotor/brake cover, that I removed, took off the caliper, took off the brakes and the piston was out pretty far. So I got a C clamp and carefully compressed it (took off the MC cover...) got everything put back together, when I moved the bike and just compressed the lever, I had brake (and ironically more play....)I did not fire it up because it is late here and I don't want my neighbors to hate me.... So I will try it out on the road tomorrow. Question I have now:
    When will this happen again? Usually that happens when the pads are gone, but there was still a lot of pad left (almost like new! and worn evenly from the looks). What are the chances of the 'O' ring for that piston being bad? Just trying to be proactive and not just throw a new caliper at it unless I have to. So again, anything that anyone can suggest....this gal would appreciate it. Thanks!!!
     
  10. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

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    A new seal for the piston may be what is needed part number 44047-83
    however some dirt may have got down the side of the piston and prevented it retracting and pushing the piston in may have cleared it
    I would tend to get a wee bit worried that it may happen again and i would pull the piston out of the calliper clean everything out and fit a new seal

    Brian