As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
#1 HYD SYS QTY READING ZERO. ALL INDICATIONS WERE NORMAL UNTIL FLAPS WERE DROPPED, THEN SYS #1 HYD QTY RAPIDLY DROPPED TO ZERO. R/H SPOILER DRIVE SERVO VALVE LEAKING OUT OF COMPONENT. REPLACED SPOILER SERVO DRIVE ACTUATOR. LEAK CHECKS GOOD