As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA - CREW PERFORMED ABNORMAL/EMERGENCY PROCEDURES WHEN DURING FLIGHT THEY RECEIVED A #1 INBOARD HYDRAULIC CAUTION AND #1 HYDRAULIC ISOLATION VALVE LIGHTS. LIGHTS WENT OFF ON APPROACH. MAINTENANCE INSPECTED THE AIRCRAFT AND FOUND THE FLUID LEVEL GAUGE ON THE RESERVOIR STUCK. THE RESERVOIR WAS REPLACED AND SERVICED. OPERATIONAL AND LEAK CHECKS WERE PERFORMED AND THE AIRCRAFT WAS RETURNED TO SERVICE.