What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED UPON ARRIVAL TO DFW DUE TO A GREEN HYDRAULIC SYSTEM LOW LEVEL ECAM. THE AIRCRAFT LANDED SAFELY AT DFW WITHOUT FURTHER INCIDENT. UPON ARRIVAL TO THE GATE FLUID WAS REPORTED LEAKING FROM THE #1 ENGINE. MAINTENANCE FOUND A TORN PACKING ON THE GREEN HYDRAULIC PUMP CHECK VALVE IN THE LEFT PYLON AND REPLACED IT PER AMM 29-11-36. A SATISFACTORY LEAK / OPERATIONAL CHECK WAS ACCOMPLISHED.