In all my 40+ years of driving I have never had a car need a new master cylinder. I've changed the front calipers and pads, rear pads, and flushed the brake fluid completely on my son's Subaru Outback, and still the brake pedal is mushy. There's no real "bite" to the brakes. What does a bad master cylinder do, or what does it feel like? The ABS light is on, but I'm assuming that non-functioning ABS would allow me to lock up the brakes and there's no way this thing will lock a wheel right now. Suggestions??