What was found
BRAKE RT & LT FAULT MESSAGE DISPLAYED ON EICAS WHEN MLG EXTENDED. WENT AROUND AND RAN QRH PROCEDURE. BOTH LEFT AND RIGHT BRAKE PEDALS WERE VERY DULL AND AIRCRAFT WAS STRUGGLING TO STOP WITH FULL PRESSURE APPLIED AND BRAKES DID NOT SEEM TO BE APPLYING EVENLY AS AIRCRAFT WAS PULLING LEFT AND RIGHT WHEN BRAKING. EXITED THE RUNWAY AND AIRCRAFT WAS TOWED TO THE GATE. EMERGENCY DECLARED. CMC FAULT CODE 32411020BCM. PERFORMED MAIN BRAKE PRESS TRANSDUCER FUNCTIONAL CHECK, MAIN BRAKE AND EMER/PARK BRAKE OPS CHECKS AND PERFORMED LOW AND HIGH-SPEED TAXI CHECKS WITH FLIGHT CREW PER EMB 170 AMM 32-41-00-720-802-A, 32-41-00-710-801-A, AND 32-44-00-710-801-A. FUNCTIONAL, OPS, AND TAXI CHECKS GOOD, NO DISCREPANCIES NOTED