As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BEFORE FIRST FLIGHT DURING HYDRAULIC TESTING, PILOT SWITCHED 'OFF' NR 2 HYDRAULIC SYSTEM. AFTER THE SYSTEM WAS SWITCHED BACK 'ON' PRESSURE INDICATION FELL OFF TOZERO. A/C WAS SHUTDOWN. SUBSEQUENT INSPECTION REVEALED THAT THE BRAIDED NR 2 HYDRAULIC HOSE FROM THE PUMP TO MIXING VALVE WAS BURST AT THE 45 DEGREE FITTING (SEE ATTACHED PHOTO). HOSE REPLACED, A/C RETURNED TO SERVICE.