As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT #1 HYD QUANTITY FELL TO 0 #1 HYD PRESS REMAINED AT 2800 PSI AFTER LANDING #1 ENG HYD PUMP CAUTION ILLUMINATED INTERMITTENTLY. EMERGENCY DECLARED. LANDING UNEVENTFUL. REMOVED FROM SERVICE. FOUND #1 HYD SYST BALANCE RELIEF VALVE LEAKING. R&R RELIEF VALVE. AIRCRAFT RETURNED TO SERVICE.