As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING DESCENT INTO KCCR CREW OBSERVED A STEADY ILLUMINATION OF THE LO HYD FLOW L LIGHT. CREW ELECTED TO DIVERT TO KOAK AFTER DISCUSSING THE POSSIBILITY OF NOT HAVING THRUST REVERSE CAPABILITY INTO A SHORT RUNWAY. EMERGENCY DECLARED BY ATC. LANDING WAS UNEVENTFUL. MAINTENANCE FOUND AIR IN THE HYDRAULIC RESERVOIR. SYSTEM WAS BLED AND SERVICE. NO DEFECTS NOTED. A SUCCESSFUL OPERATIONAL CHECK FLIGHT WAS PERFORMED. AIRCRAFT WAS RETURNED TO SERVICE.