What was found
RAMP CREW NOTICED THAT RT INBOARD (NR 3) MAIN WHEEL WAS FLAT WHILE AIRCRAFT WAS PARKED AT GATE. MAINTENANCE DISCOVERED THE NR 3 BRAKE UNIT WITH A WARPED/OVERHEATED BRAKE DISKS WHICH CAUSED THE FUSE PLUGS ON THE NR 3 MAIN WHEEL TO BLOW. MAINTENANCE REPLACED THE NR 3 BRAKE UNIT AND THE NR 3 AND 4 MAIN WHEEL ASSEMBLIES. TAXI AND FUNCTION CHECKS OF THE BRAKING SYSTEM WERE COMPLETED WITH NO FURTHER FAULTS FOUND. WHEEL SHOP CONFIRMED BRAKE UNIT DID OVERHEAT AND THAT IT WAS NOT A FAULT WITH THE UNIT.