As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 208 HNL-OGG - UPON RETRACTION OF THE LANDING GEAR AND FLAPS, THE CREW NOTED A LOUD FLUTTERING NOISE AND BUFFET. CREW RETURNED TO HNL WITHOUT FURTHER INCIDENT. MAINTENANCE REMOVED AND REPLACED THE HYDRAULIC RESERVOIR AIR PRESSURE REGULATOR PER AMM 29-09-341 AND THE HYDRAULIC RESERVOIR PRESSURE RELIEF VALVE PER AMM 29-09-351. ALL OPERATIONAL AND LEAK CHECKS FOUND SATISFACTORY. THE AIRCRAFT RETURNED TO SERVICE.