As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN CRUISE FLIGHT AT FL430, 'A' HYDRAULIC SYSTEM INDICATOR WENT TO ZERO QUANTITY. CREW RAN THE APPROPRIATE CHECKLISTS AND MADE AN EMERGENCY LANDING INTO KSDF. LANDING WAS UNEVENTFUL. MAINTENANCE TROUBLESHOT THE DISCREPANCY TO A DEFECTIVE LEFT ENGINE HYDRAULIC PUMP PULSATION DAMPENER O-RING. O-RING REPLACED, N2 BOTTLE SERVICED, SYSTEM BLED AND GEAR SWINGS WERE PERFORMED WITH NO DEFECTS NOTED. AIRCRAFT WAS RETURNED TO SERVICE.