As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURN BACK, AFTER TAKEOFF, NR 1 HYDRAULIC SYSTEM QUANTITY DECREASING, LOW QUANTITY LIGHT ILLUMINATED. ACCOMPLISHED HYDRAULIC SYSTEM NR 1 FAILURE ABNORMAL PROCEDURE, LEAK STOPPED AT 1 GALLON INDICATED. FOUND PRESSURE LINE TO TRANSMITTER LEAKING. SECURED LINE AND SERVICED SYSTEM TO FULL. LEAK CHECKED GOOD IAW AMM 29-31-01. (M)