What was found
ON FLIGHT 4224 THE CREW REPORTED THE E1 HYDRAULIC PUMP FAILED. INDICATIONS WERE ALSO A LOSS OF HYDRAULIC SYSTEM 1 FLUID AND A LOSS OF HYDRAULIC SYSTEM 1 PRESSURE. THE CREW DECLARED AN EMERGENCY AND DIVERTED TO GRR. THE AIRCRAFT LANDED SAFELY WITH NO INCIDENT. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED AND REPLACED NR 1 HYDRAULIC ELECTRIC MOTOR DRIVEN PUMP IAW EMB 145 AMM 29-10-04. REMOVED AND REPLACED NR 1 ENG DRIVEN PUMP IAW EMB 145 AMM 29-10-03. REMOVED AND REPLACED NR 1 HYDRAULIC SYSTEM FILTERS IAW EMB 145 AMM 29-10-08. OPERATIONAL AND LEAK CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE.