you probibly have the exact same problem I did... My brake fluid kept slowly getting low... I would have to fill it once a week... So I looked into it more... I let it sit overnight, then checked under my car to find nothing... Someone suggested for me to check on the inside of my back wheels (under the drum brakes) and TA DA! Brake flid was puddleing in there... my passenger rear brake cylender was shot... Basically when it went it just started to leak all of the time, and shut off power to the rear brakes, I needed a new cylender, and pads... took about 3 hours to Take it apart, clean it up, and re assemble it again with the new pads... Check out the back side s of your rear wheels next chance you get.
