What was found
ON FLIGHT 3839 CREW REPORTED AT CRUISE NUMBER 2 HYDRAULIC SYSTEM OVERHEAT FOLLOWED BY NUMBER 2 HYDRAULIC SYSTEM FAIL. AFTER AOM COOL DOWN PERIOD INITIALLY WOULD NOT TURN ON WITH EICAS SYSTEM OVER HEAT MESSAGE GONE. CREW TRIED 5 MIN LATER AND SYSTEM CAME ON. CREW DECLARED EMERGENCY AND LANDED WITH OUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED HYDRAULIC SYSTEM RESERVOIR 2 THERMAL SWITCH IAW EMB 145 AMM 29-30-05. OPERATIONAL TEST GOOD. AIRCRAFT RETURNED TO SERVICE. (A)