As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX - EN ROUTE FROM LAX TO EUG, FLIGHT CONTROL HYDRAULIC SYSTEM NOTED DECREASING IN TO YELLOW CAUTION AREA OF INDICATOR DURING FLIGHT. DIVERTED TO PDX. SERVICED AND OPERATIONALLY CHECKED HYDRAULIC SYSTEM. NO DEFECTS NOTED. AIRCRAFT RETURNED TO SERVICE.