As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) PILOT WAS DOING HIS PREFLT HYD TESTS AND THEY FAILED. AFTER TROUBLESHOOTING HYDRAULIC SYSTEM FOUND THAT ONE LATERAL SERVO WAS THE CAUSE OF THIS MOVEMENT EVEN THOUGH DURING OUR TROUBLESHOOTING THE LATERAL SERVOS WERE SWAPPED OVER BUT THE PROBLEM STAYED GOING TO THE RIGHT. REMOVED FAULTY SERVO AND INSTALLED FRESHLY OVERHAULED SERVO.