What was found
(CAN) MAINT IN YHM DISCOVERED NR 2 ENGINE NR 4 BEARING BREATHER VENT LINE ELBOW HAD PULLED OUT OF FAN CASE. LATER INVEST. MAINT FOUND THREADS TO BREATHER LINE HAD STRIPPED & LINE WAS NOT SECURED TO FAN CASING. ENGINEER RESECURED & SEALED LINE TO ENGINE & COMPLETED ENGINE RUNS WITH NO LEAKS FOUND - A/C DEEMED SERVICEABLE FOR FERRY FLT TO YYC.MAINTENANCE IN YYC REPLACED ENGINE, COMPLETED ENGINE GROUND RUNS - NO LEAKS FOUND. A/C RETURNED TO SERVICE WITH NO FURTHER INCIDENTS TO REPORT.