What was found
CREW REPORTS HYD Y RSVR LO LVL ECAM MESSAGE. YELLOW HYD SYST QTY WENT TO ZERO ON ECAM PAGE. CREW FOLLOWED QRH PROCEDURE AND SHUT OFF ENG PUMP AND ELECTRIC PUMP IN THE YELLOW SYSTEM. FLAGGED SDR FIELD DUE TO DIVERSION TO ORD ALL ISSUES RESOLVED. . REPLACED PACKING ON PTU MANIFOLD CHECK VALVE. RAN YELLOW HYD SYS NO LEAKS NOTED. REPLACED #2 ENG HYD DPI REF AMM RAN ENG LEAK CHECK GOOD. RAN ENG FOR 5 MINUTES NO LEAKS AND NO DPI POPPED. AIRCRA FT RETURNED TO AIRWORTHY STATUS.