What was found
PASSING 22,000 FT, ECAM DIRECTED GREEN PUMPS OFF AND GREEN SYSTEM PRESSURE INDICATED ZERO ON BOTH ECAM SCHEMATIC PAGE AND OVERHEAD HYDRAULIC GAGE. RAN QRH HYD SYS LO PR FOLLOWED BY HYD RSVR LO LEVEL CHECKLISTS, USED FREE FALL EXTENSION CHECKLIST, DECLARED EMERGENCY AND LANDED KIND. EMERGENCY DECLARED FOUND ELBOW LEAKING AT BOTTOM OF LANDING GEAR SELECTOR VALVE 3GA. REMOVED ELBOW AND FOUND DAMAGED O-RING. CHANGED O-RING AND BACKUP RING IAW AMM 32-31-12-04. SERVICED HYDRAULICS IAW A300 AMM 12-12-32. OPS AND LEAK CHKD GOOD IAW AMM 32-31-12-04. BLED GREEN SYS IAW AMM 29-00-00-04. RAN ENGINES IAW JRH, HYDRAULIC QTY DID NOT DROP & REMAINS IN THE TOP OF THE TOP HAT.