As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SLOW LOSS OF HYDRAULIC FLUID NUMBER 4 HYDRAULIC SYSTEM DURING FLIGHT. ENGINE DRIVEN PUMP DEPRESSURIZED AND QUANTITY HELD AT 4 GALLONS. FOUND NR 4 ENGINE DRIVEN PUMP PRESSURE LINE IN PYLON CRACKED. REPLACED LINE LEAK CHECK AND OPERATIONAL CHECK OK PER MAINTENANCE MANUAL 29-11-00.