What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED AND THE ACRT DIVERTED TO TPA DUE TO THE FLT CREW REPORTING ECAM MESSAGES FOR GREEN HYD SYS LOW PRESSURE, GREEN HYD SYS RESERVOIR LOW LEVEL & GREEN HYDRAULIC SYSTEM ENGINE 1 PUMP LOW PRESSURE DISPLAYED DURING FLIGHT. THE AIRCRAFT LANDED SAFELY AT TPA WITHOUT FURTHER INCIDENT. MAINT REPORTED THAT UPON INSPECTION DISCOVERED LEAK COMING FROM THE GREEN HYD SYS RESERVOIR DRAIN VALVE, REMOVED DRAIN VALVE IAW AMM 29-11-41. UPON REMOVAL OF VALVE DISCOVERED INTERNAL O-RING CHOPPED & JAMMED IN VALVE BODY OF DRAIN VALVE STOPPING VALVE FROM FULLY CLOSING. MAINT INSTALLED NEW DRAIN VALVE IAW AMM 29-11-41. A SATISFACTORY LEAK / OPS CHECKS ACCOMPLISHED WITH NO FAULTS NOTED.