As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING TAXI WHEN FLAPS EXTENDED HYD A SYS PRESS WENT TO 1500 PSI & BOTH A SYS LOW PRESS LIGHTS CAME ON. UPON REMOVAL OF RUDDER MODULE FOUND TEFLON BACK UP RING OUT OF PLACE & WOUND UP INSIDE THE LINE FITTING PORT. REPAIR VENDOR REQUESTED TO SEND STRIP REPORT. UNIT REPLACED & OPERATION CHECKED NORMAL.