As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI OUT, THE PILOT`S RT BRAKE BECAME INOPERATIVE. AFTER TROUBLESHOOTING SYS A, RT BRAKE HOSE WAS FOUND SEPARATED FROM THE BRAKE CALIPER. THE HOSE AND CALIPER WAS REPLACED IAW CMM 32-00-00. THE SYS OPS CHECKED GOOD AND THE ACFT WAS RETURN TO SERVICE.