Originally Posted by pacodiablo
Fill the resivoir up to the fill line and check the brake system for leaks. You may have a wheel cylinder that is leaking or some other issue that is causing you to lose fluid.
as the pads/shoes ware down the fluid level will drop in the master. this is normal and under normal circumstances you should not have to "top off" your brake fluid.
you need to do as posted above, get your brakes checked.