What was found
APPROX T/O 40 MINS S/O NOTICED HYD SYS A QTY NEAR 0. SHORTLY AFTER THAT THE SYS "A" PRESSURE STARTED TO FLUXUATE DRYING, RAN OF THE QRH CHECKLIST. SYS A HYD FLUID SHUT OFF SWITCHES WERE BOTH TURNED OFF FOR THE ENGINES NR 1 AND NR 2 AT 13/0145Z. (OFF FOR 1 20 HRS) SAFETY WIRES WERE BROKEN ON THE FOLLOWING SWITCHES, ENG 1 AND 2 HYD SHUT OFF, ALT FLAPS MASTER, GROUND PROXIMITY USED ALT FLAPS AND CRANKED GEAR. R & R NR 1 AND NR 2 ENG DRIVEN HYD PUMPS IAW MM 29-11-033-4 & 29-11-0 R & R NR 1 AND NR 2 CASE DRAIN FILTERS IAW MM 29-11-041-2. R & R THE A SYS MODULAR FILTERS IAW MM 29-11-062-3. R & R THE HYD RETURN FILTER IAW MM 29-11-102. R & R FAULTY HYD HOSE.