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Discussion Starter · #1 ·
Hi,
haven't been on the forum lately.Hoping some one may have some insight on a rear brake...The other day, my FZ6 fell over and landed on it's right side. At the time it fell over, the rear brake caliper was off (and the rear tire)..yes, I know, you're probably scratching your head and wondering how that happened..that's a whole different story..

Anyhow, when all is back to normal, I went to use the rear brake and noticed that it went all the way down. there is some resistance and when I released it, it returns back to level. When I press on it, it does actuate the caliper and brakes work, the only problem is that I can continue to press the lever to the point it stops because there is no longer enough travel. neither the MC or caliper were leaking any brake fluid. Bleeding the brakes didn't seem to work.

Would anyone know what the problem may be? I suspect that when the bike fell over, it caused the lever to move and placed pressure on the caliper to actuate in motion, perhaps this ruined the MC? any knowledge or assistance would be greatly appreciated.
 

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It's possible that you damaged the MC, but not that you damaged it and itis doing what you describe without leaking fluid. You have air in there and need to get it out.

Remember that because you had the wheel/rotor off, the pads were spread apart. It would take several strokes to gat pedal pressure back in any case.

KeS
 

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Discussion Starter · #4 · (Edited)
thank you much for your input..

I have bled the brakes like a virgin on prom night...and a visual inspection of the lines shows no visual damage. the line to the caliper is tight, no leaks anywhere..

It just gets a little resistence but never enough to make it so stiff to where it won't "bottom out" when the lever is depressed. I'm going to try the MC first and see what happens, since it does send fluid and the caliper will actuate. this may have been an issue before the bike fell over.. My rear pads are fizzed out just about with not that many miles on them so I suspect this may have been ongoing..If nothing else other than the MC is not the problem, I'll change out the caliper.
 

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Check that you don't have fluid leaking at the piston seals in the caliper. But if there's no fluid getting out, and you have a soft pedal, it HAS to be air. Not that complicated a system. Try reverse bleeding - pushing fluid up from the wheel caliper with a syringe.

KeS
 

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Is the retainer spring in?

2006 Yamaha FZ6 OEM Rear Brake Caliper | MotoSport

Part #8 in the exploded view. That little clip thangie helps push the brake pads back out when you release the brake pedel. The roters push the pads back but that little thing finishes the job. :gavel

It isn't really held in by anything. You are supposed to put a dab of grease on it to get it to 'stick' in place while you close up the caliper but I never do. If it wasn't there, you could be dragging a shoe, which would change the pressure needed to work the piston.
Do you have a helper? If so, pull the caliper off and press the pedel until you get the pads all the way out. Take your 'C'; clamp and while your helper pushes the pad back, look in the fluid resevoir and see if the fluid is backing up. It should be and if it isn't, you have something solid blocking the line. You WILL need to bleed the brake again after doing this but if the fluid doesn't move as the pads are forced back by the 'C' clamp, you need a new brake line anyway. If money is super tight, you can use an air compressor to try and blow the line clear. i have had mixed luck doing that. I think because you are fixing a symptom. What ever caused the blockage in the line might or might not be fixed by blowing the line clear.
Or you might try replacing parts of the line.
IIRC, (it's dark and snowing here, I'm not about to hobble out to the shed and look on my bike to see) the rear brake line is made of 3 seperate lines, 2 metel and one rubber. The place to look for a blockage would be where the rubber meets the metel, so to speak.
when I say blockage i also mean 'obstruction'; ie some place that isn't totally blocked off but there is something that prevents the system operating as designed.
Good Luck
:explosive
 

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Discussion Starter · #7 · (Edited)
ok...man, this has been one learning experience..before i tried anything, I looked over the internet for assistance and last stop was here to get some advice. When all was done and said, i probably uberworked the issue..
I first replaced the MC..Same thing as my initial email. I then replaced the caliper; that's a moth'fcker because it was costly, about $300 later....I went to bleed the brakes, and still no f'kn pressure.....this was about 3 weeks worth of waiting for nothing.....I stewed over it for a while, and decided I would get motivated andtake it to the bike mechanic..While on the internet, i put in some other search words and found this guy's website; Boneman's FZ6 website. There was a special topic on bleeding. One of the suggestions was to "prime" the MC first by removing the banjo bolt and placing your finger on the MC hole, then pump the lever a few times, release you finger and repeat........To my amazement, that worked........one simple step missed.I never heard to "prime" the MC but it worked. On the bright side, I have a new rear brake set and some extra used items.

Thank you all for your suggestions and advice. I hope that this news in turn will help you out someday. I guess bleeding the rear brakes on this bike is somewhat tricky.
 
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