As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT EXPERIENCED THE HYDRAULIC PUMP CYCLING CONTINUOUSLY TO HOLD PRESSURE, FOLLOWED BY PARTIAL GEAR EXTENSION. THE PILOT EXTENDED THE LANDING GEAR USING EMERGENCY PROCEDURES AND LANDED WITHOUT INCIDENT. CORRECTION ACTION INVOLVED REPLACING THE HYDRAULIC POWER PACK ASSEMBLY. SUBSEQUENT OPERATIONAL CHECKS WERE SATISFACTORY.