As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING PUSHBACK, NOTICED A VIBRATION COMING FROM THE LANDING GEAR. GND CREW THEN NOTICED SEVERAL PIECES OF METAL ON THE RAMP, NEAR THE LEFT INBOARD MAIN WHEEL. PIECES SEEM TO COME FROM LEFT INBOARD SIDE. BOTH THE NR 2 BRAKE ASSEMBLY WAS REPLACED DUE TO COMING APART AS WELL AS THE NR 2 WHEEL ASSEMBLY DUE TO FAILURE OF THE BRAKE IAW AMM 32-41-41 & 32-45-11.