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Rundel
07-14-2004, 11:40 PM
I have a 96 R1100R with 17k on it and with ABS. I've only had it since April so I'm still learning about it. I just noticed that the front master cylinder is starting to leak (the joy of buying a used bike). Is this rebuildable? If so what is necessary. Since it's ABS what are the tricks to bleeding the system. TIA.
vstatco
07-16-2004, 06:50 PM
Rundel, Hello, This is not an un-common problem. My friend had the same thing happen on a 97 R, he could not find a rebuild kit and replaced the master cylinder. I have recently heard a rebuild kit is available, the part number is: 32-72-2-332-037.

As far as bleending the brakes, even though it's ABS, bleed as normal via the valves on the calipers. However, it is possible to get air in the ABS modulator. And the only way to get it out is to bleed from the modulator bleed valves, under the gas tank. If your brakes feel normal after repairing the leak and bleeding the system, don't worry about this. Good luck and good riding!
palberini
07-19-2004, 09:58 AM
I just replaced mine on a 96 R1100RT, 16k miles. Same problem, the lever start feeling spongy and thereafter started leaking. No particular problems in replacing the part, except for taking down the heated grips.

I couldn't find a rebuilt kit, so I got a new part ($200). Better use a vacuum bleeder ($20) to get the air out. Good luck.
Rundel
07-19-2004, 09:24 PM
As an update, I disassembled the master cylinder while still on the bike. The area behind the rubber outer seal was crudded up. I was able to pull the piston and the cylinder wall was pitted from the unchanged brake fluid. I attempted to resurface with a 3M scotch pad but it wasn't agressive enough. I then resorted to more power and got out the dremel tool. I used a small drum sander to smooth things out and then used felt polishing cones and wheels to slick things up. I then cleaned out the cylinder and re-assembled. The seals on the piston looked good.

As of today, four days latter, it has weeped a little but that may be the seals re-seating. After a ride tonight, no leaking. We''ll see what happens.