As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TEARDOWN REPORT OF ENG IDENTIFIED HIGH INTERNAL LEAKAGE AT VSV ACT ALONG WITH SLOW PISTON VELOCITY. TEARDOWN REVEALED THAT CONTROL SERVO VALVE & SEAL WERE WORN BEYOND LIMITS & CAUSED INTERNAL LEAKAGE AT VSV ACT. FAILURE MODE & EFFECTS ANALYSIS CONSIDER THIS A MAJOR FAILURE & WOULD RESULT IN CSV TO M