Leaky rear master cylinder

[Lucien Harpress]

Okay, story time:

When I bought my bike, the rear brake was seized. I had to tear it apart to free all the little bits inside, and when I put it back together (correctly, I thought) and re-bled it, it seemed to work fine.

For a while.

After a few weeks the rear pedal got mushier and mushier. So, today, I try to re-bleed it. Open up the MC- uh oh. No brake fluid. No biggie, let's fill it up, re-bleed, and see what happens. Well, what happened was a nice, firm brake, and a nice leak out the MC plunger.

I know I'm going to have to, at the very least, take the MC apart again. I guess my questions are:

-Could this be the result of me putting it back together wrong, and if so, what did I do wrong (most likely)?

-If I need to re-build the MC, how difficult would that be, and (more importantly) how MUCH would it be?

-Should I be concerned about the condition of the part of the plunger connected to the brake pedal (the metal stick-type-thing), or is there just a rubber seal in the MC itself I need to worry about?

I apologize for all the dumb questions, but even though I've taken it apart once, it's amazing how quickly you forget how everything looks! Thanks in advance.

[XSokieSPECIAL]

Okay, story time:

When I bought my bike, the rear brake was seized. I had to tear it apart to free all the little bits inside, and when I put it back together (correctly, I thought) and re-bled it, it seemed to work fine.

For a while.

After a few weeks the rear pedal got mushier and mushier. So, today, I try to re-bleed it. Open up the MC- uh oh. No brake fluid. No biggie, let's fill it up, re-bleed, and see what happens. Well, what happened was a nice, firm brake, and a nice leak out the MC plunger.

I know I'm going to have to, at the very least, take the MC apart again. I guess my questions are:

-Could this be the result of me putting it back together wrong, and if so, what did I do wrong (most likely)?

-If I need to re-build the MC, how difficult would that be, and (more importantly) how MUCH would it be?

-Should I be concerned about the condition of the part of the plunger connected to the brake pedal (the metal stick-type-thing), or is there just a rubber seal in the MC itself I need to worry about?

I apologize for all the dumb questions, but even though I've taken it apart once, it's amazing how quickly you forget how everything looks! Thanks in advance.

If you had a good pedal for a while before you lost all the fluid, you probably assembled it properly. The seals are probably just worn out or damaged in some other way.

Kits are available in ebay or several other suppliers fairly inexpensively.

Need help finding one let me know. I don't have all that info in front of me right now.

[DGXSER]

Here is a link to a kit on ebay. Ive bought severla things from this guy and he really seems to know the XS11 and the differences from one model to the next. Very good person to do business with as well.