Rear master cylinder wont bleed?

Discussion in 'Sportster Models' started by UsMc16, Jul 8, 2011.

  1. UsMc16

    UsMc16 Member

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    Just found this site it seems informational anyways, trying to bleed my rear brake lines on a 05 4300miles. When i open the valve no air, no fluid. I have plenty fluid in the main canister. Im thinking i have to replace the master cylinder or would a rebuild kit suffice?
     
  2. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    Was there a "dust cap" on the bleeder nipple? Even if there was, try removing the bleeder completely and see if fluid comes out of the port in the caliper as you try to depress the pedal. If not, do you have any rear brakes?

    If fluid comes out the port, the bleeder is plugged. Replace it.

    If all above produces NO fluid out the port, rebuild the master cylinder and probably the caliper (was the wrong fluid added to the reservoir and the whole brake fluid system is contaminated). Flush the brake system with at least two reservoir volumes after rebuilding, but BEFORE hooking the supply line back to the caliper. Make sure you use the correct fluid.

    TQ
     
  3. UsMc16

    UsMc16 Member

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    Alright thx for the advice, had the right fluid im just thinking (since i bought the bike from a guy who didnt ride it for at least a year, left it in the weather an everything) just taking off the mast., cylinder cleanin it out and still if it doesnt pump ill have to rebuild it. thx again. Any advice or hidden actions i should know about to rebuild it?
     
  4. jbm614

    jbm614 Member

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    As well as what others have suggested consider a "mighty vac". I purchased one from Harbor Freight or one similiar to it.

    It is a little unit that you connect to the bleeder valve that draws the fluid from the master cylinder. I have not used it on the HD but on the old Wing
    with great results...

    Good luck with your rebuild!! This has probably already mentioned regarding this...
     
    Last edited: Jul 9, 2011
  5. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    Nope. Very simple and straight-forward. Just replace the cartridge. But I would suggest that if you need to redo the MC, you should do the caliper too. And get the rebuild kit that includes a new piston. When everything is done, but before you hook the hose back up to the caliper, flush bunches of new clean brake fluid through to clean it out too.

    TQ