As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) THE PILOT REPORTED THAT THE LANDING GEAR WOULD NOT EXTEND WHEN SELECTED DOWN. THE EMERGENCY HAND PUMP SUCCESSFULLY EXTENDED THE GEAR TO INDICATE 3 GREEN. LOW HYDRAULIC FLUID LEVEL WAS FOUND TO BE THE CAUSE OF THE PROBLEM DUE TO A CRACK IN THE THREADS OF THE RT HYDRAULIC FILTER BOWL. THE CRACK IS MOST LIKELY CAUSED BY OVER TIGHTENING THE BOWL, ALTHOUGH IT HAD BEEN IN PLACE 32.5 HOURS BEFORE THE GEAR PROBELM OCCURRED.