Help needed! I can t bleed my rear brake on a Sinnis 250 motorbike, the fluid isn t moving. I m following the instructions TO THE LETTER.?

WTF ? I ve wasted four hours on this fc job!

5 Answers

  • 6 months ago

    Take it to a shop and have a Mechanic fix it

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  • 6 months ago

    Make sure the bike is on the ground. if you have it up on a bike lift the rear brake proportioning valve may be stopping the flow of brake fluid.

    • Road Warrior6 months agoReport

      MCs have no proportioning valves.Separate F/R systems. Some very new ones Might have ABS.. This could be screwing up.

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  • 6 months ago

    Is there a high spot in the line? Are you pushing the fluid up hill? Air lock. You can try lifting up the front or rear of the bike, or clamping down the brake pedal and leaving it over night. But you may have to disconnect the banjo bolts, remove the brake hose, disassemble the master and slave cylinders and blow everything out with compressed air to really see what's going on. I've always thought hydraulic rear brakes were a bad idea. Mechanically-actuated shoe brakes never have hydraulic problems.

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    • adam
      Lv 4
      6 months agoReport

      drums are fine. Until they get hot and glaze up. My 71 FLH has its original drums. It stops eventually LOL

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  • Anonymous
    6 months ago

    Try forcing the slave pistons back as far as they can go; with large common--point screwdriver. Could be they are froze.

    Then, release banjo on master; pump, tighten. Do it a few times, Check fluid; Never let it get low.

    Then, try rebleeding slave by book.

    EDIT: If you have ABS, it might be holding you up. Get a Haynes book and see how to temporarily disable.

    I have an old Honda, you Can Not bleed the clutch the way book says. Gotta use a 50CC syringe on the slave. Open bleed nipple, suck, close. Repeat. Hold syringe Above the slave so air can rise to top. May have to dump it if it gets full. Again; Never, let reservoir get low.

    If you let res. get low, so the holes are uncovered, you have to do it All over again. You can't just refill the res.and keep trying. This allows air back in. This might be why it takes you so long.

    Last time I bled clutch ( needs be done every 6 month-1 year), I needed New fluid, Period,. I tried industrial hydraulic fluid, as it wasn't a brake.

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  • 6 months ago

    If the master cylinder is defective, the fluid won't move. You need to force the fluid with air pressure instead. Perhaps you don't have the equipment to do that. If you have a good master cylinder, it should work.

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