As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HYD Y RESERVOIR LOW LEVEL DURING FLIGHT. SUBSEQUENT Y SYS FAILURE INDICATIONS. REMOVED AND INSTALLED SERVICEABLE O-RING ON REDUCER ON PTU MANIFOLD. PERFORMED OPS CK AND LEAK CK. NO FAULTS OR LEAKS NOTED. REF AMM 29-13-15 PB 401, PG 5, STEP 4 A (2) (E) AND (F). OPS CHECKED IAW AMM 29-13-00-710-002.