As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AFTER TAKE OFF THE CREW SELECTED THE FLAPS UP. ONCE THE FLAPS CAME UP THE HYDRAULIC PRESSURE IN THE MAIN AND STANDBY SYSTEMS DROPPED TO ZERO. THE HYDRAULIC QUANTITY REMAINED NORMAL. AS THE AIRCRAFT RETURNED FOR LANDING THE HYDRAULIC PRESSURE IN THE AFFECTED SYSTEMS BEGAN TO INCREASE. MAINTENANCE CREWS REPLACED THE NR 1 ENGINE DRIVEN HYDRAULIC PUMP.