As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BOS - FLT 4390 - ON CLIMB-OUT, CREW EXPERIENCED A LOSS OF HYDRAULIC PRESSURE AND QUANTITY. CREW SELECTED GEAR DOWN AND RETURNED TO BOS. AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND HYDRAULIC LINE CONNECTING TO HYDRAULIC PUMP BROKEN. LINE REPLACED AND SYSTEM SERVICED. AIRCRAFT RETURNED TO SERVICE. (X)