Ducati Monster Forum

So I have what seems to be bad brake fluid with water/air in the system because when I pull the front brake lever it works but then slowly loses resistance till it doesn't hold the bike at all.  It also squeaks when I roll the bike which I think is probably the brakes not fully releasing.  I'm planning on replacing the brake fluid in a few days but my question is, am I correct and could this be caused by what seems to be a broken gasket on the brake fluid resevoir?  If it is where do you suggest to look for a replacement gasket? Thanks,
Mac
(http://i9.photobucket.com/albums/a99/Cypherzion/P1000644.jpg)

Sounds like your master needs a rebuild, or at least a thorough cleaning; it seems the primary seal on the piston is compromised.

Yeah - you're losing pressure some place.  Check from the calipers back for signs of leaks.  But Speeds probably right that you're master might be toast.

The gasket in the reservoir would have no effect like you describe.  It's there to prevent moisture from getting into the fluid.  It's not a seal in the pressurized system

the bike only has 2700 miles on the odo....could the master cyl need a rebuild after so few miles...it's a 2005 and has sat a lot.  could it have anything to do with the fact that I dropped the bike at a stop?  It didn't show up until then....Maybe someone from the board can drop by to check it out...I've had this bike for less than a week and I can't ride it :(

sorry, I ment to add that the broken seal could have caused water/air to get into the system causing these problems

A master can be new and be defective.  You can try bleeding the brakes.  Did you check the fluid level?  While checking the fluid level you can inspect the gasket and the fluid for contamination.

I bled the brakes yesterday and there was air in them...the seal was bad for the reservoir cover and the guy that was helping me thinks the master cylinder is bad...when I squeeze the lever with the cap off it shoots fluid 3ft in front of the bike and when I squeeze the lever witht\ he cover on, fluid runs down the side of the reservoir(causing the thought that the seal is bad).  The guy who was helping me hasn't worked with the s2r style brakes before tough so he wasn't sure if the squirting thing was normal or if it was busted.  After I thought about it the fall that the bike took was strong enough to bend the front brake lever 90* so it might have been enough to make the master fail.  I want to make sure before I buy a new master though :-\

With the cap off, yes, the master will shoot fluid like that.
Pull the lever slowly if you've got the cap off.

If you bleed it, and the lever stays firm, and won't go to the bar if you squeeze it hard for a minute or two, then it should be OK.

I bled the brakes yesterday but when I replaced the lever today I squeezed the lever pretty hard and it slowly lost enough pressure to touch the bar.....could this be because of the failed gasket/seal/whatever it is?  this is really depressing.....I really hope that it isn't to hard to fix  :-\

The problem is an internal seal, not the diaphragm on the reservoir cap.  I don't know how the availability is on overhaul kits, but a new master is not expensive and, hey, we are talking brakes here.

http://www.yoyodyneti.com/ProductInfo.aspx?productid=10.4620.86

It even comes with a a brand spankin' new lever.  If kits are available Fred at Yoyodyne would know.

Hey I had a simialar problem with my 695. I think you may have got some air in there. Before you replace it try something. How did you bleed the brakes, real methodically? Loosen, squeeze, tighten, release, repeat? When I did it that way I absolutely could not move enough fluid through the lines to dislodge a persistant bubble where the lines meet. The way I finally solved it was to fill the resorviour completely to the top and place the lid(minus the rubber gasket) on the coffin to prevent fluid going everywhere. I then loosened one side and just pumped the ever livin' shit outta it. I then tightened that nut, refilled and did the other side, I did it twice on either side and finally got the bubbles out. It's worth a shot before you buy a rebuild kit anyway.