As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING FLT CREW AND MTC WALK AROUND CHECKS, THE AIRCRAFT`S MAIN HYDRAULIC SYSTEM FILTER HOUSING ASSY WAS CRACKED AND HAD FAILED. FILTER HOUSING ASSY LOCATED NEAR AC HYDRAULIC PUMP ASSY. THE MAIN HYDRAULIC SYSTEM FILTER HOUSING ASSY WAS REPLACED AND THE AIRCRAFT RETURNED TO SERVICE. ALL SUBSEQUENT OPERATIONS WERE NORMAL. (TC# 20180103010)