As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE, SYS B HYD SYSTEM LOW PRESSURE LIGHT CYCLED ON AND OFF EVERY 10 SECONDS. CHECKED MFD SYS PAGE AND NOTED THE B SYS QTY AT 0. TURNED OFF B SYS PUMP. B SYS PRESSURE REMAIND AT 2900. NO M/C LOW PRESS LIGHT. DECLARED EMERGENCY, LANDED NORMAL. MAINTENANCE FOUND HYD SUPPLY LINE TO NR 2 ENGINE DRIVEN HYD PUMP LOOSE. TIGHTENED THE LINE IAW AMM 29-11.