What was found
(CAN) ON THE FIRST DEPARTURE AFTER AN ENGINE DRIVEN HYDRAULIC PUMP REPLACEMENT, AFTER SELECTING GEAR UP THERE WAS AN A SYS HYDRAULIC LOW PRESSURE INDICATION WHICH LASTED APPROXIMATELY 30 SECONDS. 10 MINUTES LATER THE HYDRAULIC LOW PRESSURE INDICATION RETURNED. THE ACFT DIVERTED. MAINTENANCE FOUND THE CASE DRAIN QUICK DISCONNECT FITTING IMPROPERLY INSTALLED CAUSING THE PUMP TO FAIL. THE PUMP AND QUICK DISCONNECT FITTING WERE REPLACED AND THE HYDRAULIC SYSTEM FLUSHED AND FILTERS REPLACED.