What was found
DURING CLIMBING, APPROX 16,000', RECEIVED ECAM WARNING ON HIGH BRAKE TEMP. LOWERED LG TO COOL BRAKES & RETURNED TO TAKEOFF AIRPORT. WHILE ACFT PARKED AT THE GATE, SUSPECT NR 4 MLG TIRE FUSE PLUG BLOWN. A BRAKE OVERHEAT INSPECTION IS REQUIRED IAW AMM 05-51-16-00. FOUND NR 4 BRAKE TO BE BROKEN INTO PIECES ON NR 4 MAIN BRAKE ASSEMBLY IN SEVERAL LOCATIONS. R & R NR 4 BRAKE ASSEMBLY IAW AMM 32-42-27-04. BLED BRAKES & PERFORMED OPS CHECK OF BRAKE UNIT. R & R NR 4 MLG TIRE IAW AMM 12-37-32-00-02. PERFORMED TEST OF BRAKE FANS, TIRE TORQUED TO LIMITS. PERFORMED & COMPLIED WITH BRAKE OVERHEAT INSPECTION OF NR 4 MLG AXLE & ASSEMBLY. R & R NR 3 MAIN TIRE IAW AMM 12-37-32-00-02.