As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE TAXIING WE WERE PERFORMING OUR USUAL TAXI CHECKS. AFTER PERFORMING THE BRAKE CHECK AND BEGINNING A TURN TOWARDS RUNWAY THE BRAKE SYSTEM DID NOT DISENGAGE. WE WERE UNABLE TO TAXI THE AIRCRAFT. DURING TOWING OF THE AIRCRAFT TO THE RAMP THE LEFT BRAKE COMPLETELY LOCKED UP WHICH REQUIRED THE AIRCRAFT TO BE FIXED ON THE TAXIWAY. BRAKE ASSEMBLY REPLACED.