What was found
DURING CRUISE FLIGHT ECAM DISPLAYED HYD , HYD RSVR LO LEVEL , GREEN SYSTEM OVERHEAD GAUGE SHOWED QTY AT APPROX RED DOT , ECAM HYD PAGE DISPLAYED APPROX THE SAME . EMERGENCY DECLARED. FOUND GREEN SYS PRESS LINE ON BRAKE SYSTEM MANIFOLD (1311) LEAKING WHEN BRAKES DEPRESSED. REMOVED AND REPLACED DAMAGED PRESS LINE ON BRAKE SYSTEM MANIFOLD (1311). LEAK CHECK OF REPLACED LINE GOOD. PERFORMED BLEEDING OF NORMAL BRAKE SYSTEM FROM THE FLIGHT COMPARTMENT. NO FURTHER DEFECTS NOTED.