What was found
AT CRUISE GOT GREEN HYD LOW QTY. BOTH ECAM AND OVERHEAD GAGE SHOWED ALL FLUID LOST. USED MANUAL GEAR EXTENSION. AFTER LANDING, GREEN HYD QTY BACK INTO GREEN RANGE, BUT BELOW TOP HAT. EMERGENCY DECLARED AFTER BREIF WITH FLIGHT CREW, WHEN ECAM MESSAGE APPEARED BOTH GREEN SYSTEM ENGINE DRIVEN PUMPS WERE TURNED OFF AND GREEN SYSTEM STILL SHOWING FLUID QTY ONCE ACFT WAS PARKED IN GATE. SERVICED GREEN HYD SYSTEM PER AMM 12-12-29-00-0 OPENED ACCESS PANELS 415AL,473AL,474AR, ON #1 ENG PYLON, NO LEAKS WITH JUST ELECTRIC AUX PUMPS, OPENED ENG START VALVE BY HAND & FOUND GREEN SYS MANIFOLD IN PYLON LEAKING AT MANIFOLD AND NON-RETURN VALVE FOUND HYDRAULIC CHECK VALVE ITEM 60 ABOVE REF IPC WITH BLOWN O-RING ITEM 70 ON NR 1 PYLON HYDRAULIC GREEN MANIFOLD AS SOURCE OF GREEN SYSTEM LEAK. R & R BLOWN O-RING MPN# NAS1612-16. TOPPED OFF GREEN SYS TO MIDDLE OF TOP HAT & RAN BOTH ENGINES AT IDLE MOVING ALL FLT CONTROLS. LEAK & OPS CHKD GOOD. ALL SYS SHOW MIDDLE OF TOP HAT NOW. OK FOR SERVICE.