YZ450F Front Brake(07)

1 reply to this topic
  • CL2D24

Posted July 24, 2008 - 08:56 AM


Did a world class bike drop in the garage and bent the front brake lever badly(bike fell on the right side).Replaced the brake lever with no other damage noted. Now the brake lever has good resistance for about 5 seconds ,then the lever will eventually come all the way back to the throttle in about 20 seconds with steady pressure on the brake lever with eventually no brake pressure at all on the pads. Front wheel turns freely with front brake lever pulled all the way in. Bled the brakes the old fashioned way and with a siphon,replaced master cylinder kit, held the calipers over the master cylinder and still have the same problem. Tried pretty much everything I have seen on other brake problems here with no results. No fluid leaks found anywhere. Any ideas? Other than dron't drop the :ride: anymore.

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  • grayracer513

Posted July 24, 2008 - 09:56 AM


Well, yeah, I'd stop dropping it if I could, but the symptoms you describe are a classic leaking master cylinder front piston (the one nearest the output port that forces fluid to the caliper). Since you have made the logical move to reseal the M/C already, I'm afraid that this indicates the cylinder is bent so that the bore is out of round, and can't be sealed.

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