As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
A/C WAS BEING PUSHED BACK WHEN PILOT APPLIED BRAKES, THE NR 2 BRAKE SHUTTLE VALVE STARTED LEAKING. MAINTENANCE REMOVED AND REPLACED THE NR 1 AND 2 BRAKE CONTROL VALVES AND NR 1, 3 AND 4 BRAKES IAW EMB 145 AMM 32-49-03. OPS CHECKS WAS GOOD AND A/C RELEASED.