What was found
FLT 667 BUF-MCO, CREW DECLARED EMERGENCY DUE TO BRAKE HOT ECAM AT 35000FT. PG SHOWED BRAKE NR 2 FLUCTUATING BETWEEN 310-450 INITIALLY TEMP APPEARED TO COME DOWN BELOW 300 MOMENTARILY THEN STARTED TO RISE SPORADICALLY TILL READING 750-850 AND STAYED THERE UNTIL CREW WERE ABLE TO PERFORM THE ECAM ACTION OF LOWERING THE GEAR. BRAKE TEMP CAME STEADILY AND STAYED WITHIN NORMAL RANGE 60-80 FOR THE REST OF THE FLIGHT BRAKE NR 1 STAYED 65-70 THROUGHTOUT AND GOT COOLER LATER IN FLIGHT (BRAKE TEMPERATURE MONITORING UNIT). REMOVED AND REPLACED LT MLG BTMU IAW AMM 32-27-18. OPS CHECK OK.