As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING TAXI, CREW REPORTED THAT THERE WAS SOME DRAGGING FELT WHEN THE BRAKES WERE APPLIED. THE AIRCRAFT RETURNED TO THE BLOCKS. A DETAILED INSPECTION WAS CARRIED OUT AND NR 4 BRAKE WAS FOUND UNSERVICEABLE. THE BRAKE PADS WERE DAMAGED AND BROKEN. A SERVICEABLE BRAKE WAS INSTALLED IAW MM 32-41-31 AND CHECKED SERVICEABLE. THERE WAS NO PROBLEM DURING SUBSEQUENT FLIGHT.