As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE GREEN SYSTEM AUX HYD PUMP CYCLES ON AND OFF WITH MAIN PRESSUE AT 0 PSI. SUSPECT THE ENGINE PUMP CHECK VALVE TO BE AT FAULT LETTING AUX HYD PRESSURE TO REACH THE HIGH PRESSURE SWITCH CAUSING THE AUX HYD PUMP TO CYCLE ON AND OFF. THE RESERVIOR ASSY WHERE THE CHECK VALVE WAS INSTALLED WAS REMOVED FOR ANALYSIS PER NTSB INVESTIGATOR.