As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INBOUND TO BOSTON LEFT HYDRAULIC ENGINE DRIVEN PUMP LOW OIL PRESSURE LIGHT ILLUMINATED. PUMP WAS TURNED OFF. LEFT SYSTEM QUANTITY WENT TO ZERO. REPLACED LEFT ENGINE DRIVEN PUMP. REPLACED PRESS AND SUPPLY QUICK DISCONNECT. REPLACED FILTERS ON EDP AND ACMP. REPLACED LEFT HYDRAULIC SYSTEM PRESS TUBE ABOVE LEFT PYLON PRESS MODULE, LEAK CHECKS GOOD. SERVICED LEFT HYDRAULIC RESERVOIR.