After changing my brake fluid several days ago to ATE 706302 Original Super Blue Racing DOT 4 Brake Fluid I have been having problems. The pedal feels mushy and the front passengers side brake makes a grinding sound and occasionally shakes the steering wheel under hard braking. I originally diagnosed this problem as air in the brake lines so I bleed the brakes on two separate occasions with no noticeable improvement (I only had a few small bubbles of air come out during each bleeding session). What should I do? It's a 2008 WRX by the way.