What was found
(CAN) AIRCRAFT SUFFERED HYDAULIC FAILURE. PERFORMED EMERGENCY GEAR EXTENSION AND LANDED SAFELY. HYDRAULIC LEAK FOUND ON ENGINE DRIVEN HYDRAULIC PUMP. THE END CAP FACEPLATE HAD A BROKEN BOLT AND THE BOLT IT WAS LOCKWIRED TO BESIDE IT HAD BACKED OFF. WITH BOTH BOLTS INEFFECTIVE, THE SEAL BLEW OUT BEHIND THE FACE PLATE AND ALL OF THE HYDRAULIC FLUID WAS PUMPED OVERBOARD. SUSPECTED PREVIOUS OVERTORQUING OF BOLT MAY HAVE CAUSED THE FAILURE (TC# 20060706008)