What was found
DURING DESCENT THROUGH 20,000', -A- HYDRAULIC QUANTITY DROPPED BELOW 16%. DROPPED TO 13% BEFORE UNLOADED. PNEUMATIC GEAR BLOWDOWN AND EMERGENCY BRAKE WERE USED. AFTER SHUTDOWN, HYDRAULIC FLUID COULD BE SEEN FROM THE CENTER OF THE FUSELAGE NEAR THE MAIN GEAR UNDER THE FUSELAGE TO THE TAILCONE. TROUBLESHOT AND FOUND THE HYDRAULIC PRESSURE TRANSDUCER TO BE LEAKING. REPLACED THE O-RING WITHIN TRANSDUCER. OPS AND LEAK CHECKED GOOD IAW AMM 29-20-01, & 29-30-01. SERVICED THE -A- HYDRAULIC RESERVOIR, PERFORMED A HYDRAULIC BLEED. LEAK AND OPS CHECKED GOOD.