What was found
RT BRAKES NOT BRAKING SYMETRICALLY. DURING TAXI BRAKES BEGAN TO BRAKE UNEVENLY. WHILE PRESSURING BOTH LT AND RT PADS, LT BRAKE BECAME MORE EFFECTIVE AS RT BRAKE BECAME HARDER WHICH PULLED AC TO THE LT REQUIRING RT RUDDER TO MAINTAIN CENTERLINE. THIS SEQUENCE OCCURRED SEVERAL TIMES BEFORE A SPEED WAS REACHED WHERE DIRECTIONAL CONTROL WAS COMPROMISED AND CONTROLS WERE TRANSFERRED TO LT PILOT WHEN CONTROL WAS TRANSFERRED BACK TO RT PILOT BRAKES SEEMED TO OPERATE NORMALLY. BLED BRAKES. PERFORMED MIXING VALVE CHECK IAW MM 32-40-00. OPS & LEAK CHECKED GOOD.