As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ON TAXI OUT, CREW EXPERIENCED AN EXCESSIVE DROP IN HYDRAULIC PRESSURE WHILE OPERATING THE FLAPS. THE ACFT RETURNED TO THE RAMP WHERE MAINTENANCE DISCOVERED THE ELEVATOR HYDRAULIC MODULE BYPASSING INTERNALLY. THE MODULE WAS REPLACED AND THE ACFT RETURNED TO SERVICE.