Hi, sortof a noob question but I've noticed my front brake fluid is well below the "level" indicator and I think it's getting lower every month, nearly below the little circular window now. I'm wondering (a) how crucial is brake fluid level to the longevity of the front brakes, (b) how to top off the fluid myself? the manual says to take it to a dealer but surely it's easier than that, as long as I don't get air in the lines, and (c) where to get brake fluid? Thanks!!