As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR RETURN BACK TO LAX DUE TO ENGINE 4 SURGE. ENGINE 4 SURGED MULTIPLE TIMES DURING CRUISE, SURGE WAS INTERMITTENT. PERFORMED SURGE CHECKLIST. REMOVED AND REPLACED VSV ACTUATOR LEVER PIVOT BRACKET & BOLT/STUD AS PER AMM 72-36-00. OPS CHECK GOOD.