OK, there are really only two reason why your brake fluid would be low (actually three, but one involves a jilted ex-wife and side cutters...but I digress). One reason is that you may have a leak in one or more of your brake lines, if you do have a leak it normally is on the front of the vehicle. You would find it on the rubber line that is between the metal brake line and the front caliper (usually where the rubber line is secured to the body). A leaky brake line will give you a "Spongy" feeling. #2). If your brake pads/shoes are worn down to almost the backing plate, the amount of fluid it takes to push the pads in on the rotors may have caused the master cylinder to suck air into the brake lines. If that is the case, you will have to "Bleed" all four lines. As long as you are bleeding the lines, you might as well bleed all of the old fluid out and replace it with new stuff. (If the brake fluid is really old, it can absord water from the heating/cooling cycle of the fluid. If there is water in the brake fluid, you will get a spongy feeling too).
Sep 10, 2009 at 8:32 AM
