As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
VISUAL APPROACH RWY 28L, SELECTED GEAR DOWN. A FEW SECONDS LATER, GOT NR 2 HYD ISO VALVE CAUTION, OBSERVED LOW HYD QUANTITY IN NR 2 SYSTEM. REPLACED HYD LINE ASSY FOR LT MLG DOOR CLOSE LINE SYSTEM OPS CHECKED WITH NO DEFECTS NOTED. RETURN TO SERVICE.