Obvious signs of leakage would point to a failing brake master cylinder.  The brake master cylinder tends to leak on the brake booster in the engine bay.  Check for signs of the black paint peeling underneath the brake booster.  There are brake master cylinder rebuild kits available for a very attractive price, but we recommend swapping in a whole new unit for less headaches.  Original brake master cylinders are not guarantee to work after a rebuild kit; pitting or scoring of the inside bore will not be fixed with a rebuild kit.  The brake master cylinder bore needs to be rehoned for the rebuild kit to work properly.  Most people don't have the tools to properly rehone the bore, so it's a lot easier just to get a new unit.

If you're loosing brake fluid mysteriously, but you can't see any obvious signs of leaks, check all the brakes lines in the wheel wells first.  If the brake lines are not leaking, the brake master cylinder can develop an "invisible" leak.  Changing the master cylinder will usually solve the problem.

If your brake master cylinder is original, we highly recommend to change it now just for preventive maintenance.  All the hydraulics tend to fail at this point in time for all FC3S models.

Questions?  Comments?  Send mail to:  reted@fc3spro.com