What was found
ECAM ALERTED HYD RSVR LO LEVEL ON GREEN SYSTEM. ALL INDICATIONS (GAUGE, ECAM SYNOPTIC) SHOWED AND VERIFIED. QRH CONSULTED AND COMPLIED WITH MANUAL GEAR GRAVITY EXT PROCEDURES ACCOMPLISHED. TOWED TO GATE DUE NO NOSE WHEEL STEERING. T/S FOUND HYD LEAK FROM GREEN HYD MANIFOLD FITTING FOUND O-RING CUT. REPLACED O-RING PER SMP. LEAK CHECK GOOD. RESTORED LANDING GEAR FREEFALL SYSTEM TO NORMAL OPERATING CONDITION PER A310MM CHP 32-33-00-2 PG 201-202.