As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE AIRCRAFT WAS CLIMBING TO 37,000 FT WHEN THE LOW HYDRAULIC RESERVOIR HEAD PRESSURE LIGHT COME ON. THE PILOT DESCENDED TO 20,000 FT IAW THE FLIGHT MANUAL. WE FOUND THAT THE NR 2 HYDRAULIC RESERVOIR OVER PRESSURE RELIEF VALVE WAS LEAKING. THE VALVE WAS PURCHASED FROM MFG ON 11-20-03, IT WAS A NEW PART.