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Needing help to make brakes work

Discussion in 'Maintenance and Servicing' at netrider.net.au started by 3lud13, Jun 22, 2015.

  1. OK so firstly bike is a 2000 kawasaki klr250, I have never ridden it except couple test runs up back alley bought it in pieces and been putting it back together. This is the first bike I have worked on but am pretty mechanically minded.
    Been trying to bleed the front brakes (rear is drum) had them kind of ok but then had to reroute cable and not been able to get them even remotely ok since.
    Have installed new brake pads.
    Master cylinder sucks down rubber seal or whatever it is underneath lid if fluid gets too low in it, I am guessing that is what its meant to do.
    Caliper isnt siezed as it does move though it is stiff, should it be easily moved or not.
    Have brakes working ok if at standstill or slow speeds but any speed and they not overly effective.
    Would like this issue solved asap as its pretty much the only thing keeping me sending it off for a roadworthy.

  2. Don't stuff about with brakes. If you aren't sure go to a bike mechanic.

    But things that normally go wrong are spongy brakes due to air in lines or hoses gone soft ; or leaks somewhere in line including the main reservoir seal. That was given that pistons aren't seized and pads/shoes are good as you suggest.
  3. I spoke to mechanic about it today (the one I plan on taking it to roadworthy) they gave me some suggestions to try but I have informed them it may require there attention.
    Have just tried reverse bleeding with a syring on caliper as what was suggested to me elsewhere seems no air is in system as no air bubbles coming out but still very soft lever. Maybe a rebuild or replacement of caliper or master cylinder is required.
  4. Soft lever could be master cylinder seals gone. But could also still be air in there. You can try loosening the brake reservoir cover and cable tying the brake lever on overnight. That can sometimes get rid of stubborn bubbles that lurk in bends or junctions of the line.
  5. If you rebuild the calliper, make sure you track down some red rubber grease. Many guides say to use brake fluid on the seals and things when putting them together, which does work okay, but brake assembly lube has that name for a reason :).
  6. Have ordered a master cylinder rebuild kit and have some left over rubber grease that came with my fork seals. If rebuilding master cylinder doesn't solve the issue may have to go to the other end and rebuild the caliper I guess.
    Hopefully end result will be good brakes with a firm lever