What was found
SYS A QUANTITY 18 PERCEN T AT CRUISE. PRESS 3000 RAN QRH. MANUAL GEAR EXTENTION, NORMAL LANDING. HYD ANNUNCIATOR ON SIX PACK FLASHED BRIEFLY AND FLIGH CONTROL LIGHT ILLUMINATED. TECH FOUND SYSTEM A RESERVOIR EMPTY. LEFT WHEEL WELL IS SOAKED WITH HYD FLUID. TECH LOOKING FOR SOURCE OF LEAK. PRESSURIZED HYDRAULIC SYSTEM AND FOUND LEAK COMING FROM SYSTEM "A" ACOUSTIC FILTER ELBOW. REMOVED AND REPLACED SYSTEM "A" ACOUSTIC FILTER ASSY IAW AMM 29-11-27. PERFORMED OPERATIONAL CHECK AND NO LEAKS NOTED. SERVICED SYSTEMS A & B TO 95 IAW AMM12-12-00.