What was found
FLT NR 0318 - EWR - THE LEFT HYDRAULIC SYSTEM FLUID QUANTITY BEGAN TO DECREASE WHILE IN FLIGHT. THE AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND A RUPTURED O-RING ON THE CAPPED END OF VALVE ASSEMBLY LEADING TO LEFT BRAKE PRESSURE TRANSMITTER. THE O-RING WAS REPLACED AND THE LEFT HYDRAULIC SYSTEM WAS SERVICED. THE LEFT ENGINE WAS RUN AND ALL HYDRAULIC FLIGHT CONTROLS WERE CYCLED WITH NO LEAKAGE NOTED. (Z)