I need some repair info. After installing new front brake pads on my 2004 SE, I noticed that the brake pedal felt spongy. Bled all four wheels; the right side front and the left side rear bled fine but I got very little fluid or air out of the left front and right rear. Pulled master cylinder and noticed fluid behind it going into power booster. Replaced master cylinder, but with same result. Basically, left front and right rear brakes don't work. Does this car have a proportioning valve, maybe built into the ABS module, and wouldn't it work front to back, not diagonally? Any help would be greatly appreciated!