What was found
UPON GEAR RETRACTION AFTER T/O SYS A FLUID QTY WENT TO ZERO. LT MAIN GEAR REMAINED EXTENDED. SYS A PUMPS AND FLUID SHUTOFF SWITCH WERE TURNED OFF FOR APPROX 25 MINS WITH ENGINES RUNNING. GEAR MANUALLY EXTENDED. FOUND RETRACT LINE BLOWN ON LEFT GEAR. REMOVED AND REPLACED NR 1 ENG HYD PUMP PER M/M 29-11-033-4, NR 1/2 CASE DRAIN FILTERS PER M/M 29-11-041-2, THE RT GEAR RETRACT HOSE TO THE ACTUATOR. THE NR 2 ENG HYD PUMP PER M/M 29-11-033-4,29-11-033-4. RAN ENGS PER JRH, CYCLED ALL FLIGHT CONTROLS TO REMOVE AIR FROM SYS. REMOVED AND REPLACED "A"SYSTEM PRESSURE FILTERS PER MM 29-11-062-3. LEAK CHECKS OK.