As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURN BACK NR 4 HYDRAULIC SYSTEM LOST JUST ABOVE V1 ON TAKEOFF. SYSTEM WENT TO ZERO PRESSURE AND QUANTITY. EDP WAS PLACED TO SUPPLY OFF. FOUND WING GEAR SELECTOR VALVE IN RT WHEEL WELL LEAKING. REMOVED AND REPLACED VALVE PER 32-31-03, OPS AND LEAK CHECKED OK. HYD PUMP AND FILTERS REPLACED ALSO SEE LOG PAGE 193806.