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Discussion Starter #1 (Edited)
Hello,

I'm trying to flush the brake fluid in my 2002 R6. However, I can't pump the front brake because the piston thing in the master cylinder is stuck in...



The bike has been sitting in a garage for over a year. I took the master cylinder apart and verified that there wasn't anything obstructing the flow of brake fluid. I also inspected the rubber piece in the cylinder and there doesn't appear to be any cracks or holes, at least from what I can see. So, how can I bleed the brakes now? Do I need a vacuum pump?

Additionally, my fuel light won't turn off (Change fuel filter?) and my brake lights stay on, as if I'm holding down the brake all the time. Any suggestions on these issues would be appreciated as well.

Thanks for the help!
 

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Just get a new mc used off another bike, so cheap.

I'm almost guessing the rear brake switch is jammed in causing the lights to be on all the time. Could be other things but check that.

Being a 10 year old bike in this state of repair, im betting it needs every service imagineable.
 

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Discussion Starter #3
Thank you for the replies. It turns out I was finally able to get it apart, but now I'm having trouble once it's back together.

I cleaned all the parts and the inside of the MC. The spring feels good, but it seems like the rubber pieces don't allow it to move freely.



It doesn't really have any spring action...I need to push on it pretty hard just to get it to move at all. Should I lube with some brake fluid?

Thanks again!
 

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Discussion Starter #4
Indeed, the brake-fluid-as-lube worked like a charm...but now I can't get the front bled.

I pump/hold, open nipple, close nipple, release, and repeat for about 15 minutes. Nothing on either side...
I also tried to pump/hold, open MC screw, close MC screw, release. Nothing resulted from that either.

Work in progress....
 

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Discussion Starter #5
So I took the MC off again and I covered the banjo bolt hole with my thumb and pumped the lever to see if there was pressure and there was, but I'm not sure how much is supposed to be there. I could just feel and hear a little bit of suction when I removed my finger. Also, since I left the reservoir with brake fluid attached while doing this, I could dump a little fluid out of the MC after testing with my finger.

I was doing some more research and saw that someone mentioned filling the MC with fluid before putting the banjo bolt back on. Should I dump fluid in there and carefully put it back on? Could this help?

Thanks for all the help!
 

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Discussion Starter #6
So I'm still playing around with the front brakes and I'm starting to think it is something besides the MC.

As I stated before, if I cover the hole on the MC that the banjo bolt screws into and pump the brake, I can feel the pressure; it's somewhat sucking my thumb into the hole. (Shouldn't it be pushing out though?). Today, I dumped fluid in the MC and covered the hole again with my thumb. This method creates a lot more pressure and only lets me do a few pumps. If I let my thumb off a little, air and fluid shoot out.

I reconnected the lines to the MC with the MC filled with fluid and proceeded to bleed the brakes. The first time I opened the bleed screw, air and fluid shot out. But after that...nothing.

So now I'm wondering if I have a crack in one of the brake lines. I took one of them off, but I can't really inspect it because of the rubber sleeve that fits over it. I don't really want to cut it off because I imagine it's there for a reason. There has to be some other place that air is getting to the system...

Any ideas? I really don't want to have to buy new brake lines if I don't need to.
 

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Discussion Starter #7
Figured I would update the thread...I finally got the brakes fixed.
I ended up getting a MityVac and, sure enough, it worked. :banana
 
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