Brake Failure light likes to flicker on

Discussion in 'Airheads' started by losercharles, Sep 24, 2004.

  1. losercharles

    losercharles it's just a rash

    Joined:
    Jun 24, 2004
    Oddometer:
    387
    Location:
    Austin TX
    Today, I notice that my brake failure light started to flicker. COuld this be due to low fluid level? What causes the light to actually come on? I hate that brake fluid is hidden underneath the tank ('76 r/90) Any suggestions on what I should break first to fix the brake?

    Thanks
    -Losersteve!
    #1
  2. Solo Lobo

    Solo Lobo airhead or nothing

    Joined:
    Mar 16, 2004
    Oddometer:
    9,169
    Location:
    Shoreline, WA
    Pull the tank and check the brake fluid level...then promptly throw away the under-the-tank master cylinder and replace with the later kind that mounts on your bars!
    #2
  3. Eurobiker

    Eurobiker Vintage Cat Herder

    Joined:
    Apr 23, 2002
    Oddometer:
    6,033
    Location:
    Albuquerque, NM
    The terminals on the cap are prolly shorting to the tank creating your flicker. Pull the tank and insulate the connectors with silicone, electrical or duct tape. Total repair cost, $.10 plus the :slurp you now owe me. :deal As long as your in there though, I'd change the brake fluid and bleed the system if this hasn't been done in the past 2 years. Make that 2 :slurp
    #3
  4. racer

    racer Long timer

    Joined:
    May 5, 2004
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    1,627
    Location:
    Indiana
    Sounds like a grounding problem.
    #4
  5. Flash

    Flash Sand Boxer

    Joined:
    Dec 28, 2001
    Oddometer:
    3,163
    Location:
    Sarasota, FL
    There's a float underneath the brake reservoir cap. Fluid level goes down, float sinks, closes circuit, light comes on.

    Flickering light? As stated before, check the fluid level. If OK, then disconnect the two wires and tape them out of the way. Reinstall tank and go for a ride. If flickering stops, you've got a bad cap. Most likely problem.

    If the flickering ontinues, :eek1 you've got a short elsewhere.

    My 78 R100S does it too. And the culprit is the rear master cylinder cap. To get a new cap, I have to buy the whole reservoir.

    I should have enough saved by New Year's.
    #5
  6. losercharles

    losercharles it's just a rash

    Joined:
    Jun 24, 2004
    Oddometer:
    387
    Location:
    Austin TX
    Ouch, dude.... So with that said it's probably just best to convert to a later handle bar mount. Some old fella who works on BMWs says that I could just slap a Suzuki Master Cylinder on it, but then I fear I may have to start pulling 60 mph wheelies and perform stoppies on my new squidmobile... only time will tell!


    -LoserSteve!
    #6