As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN FLIGHT HYD QTY LOW, NR 4 INDICATING .34. AFTER LANDING .74. FIM 29-11/884. EXTERNAL LEAK CHECKED IAW AMM 29-11-00 AND FOUND RUNNING LEAK AT GROUND SPOILER CONTROL VALVE B-NUT. TIGHTENED THE B-NUT AND LEAK CHECKED OK. SYSTEM NR 4 SERVICED IAW AMM 12-12-01. SYSTEM NR 4 PRESSURE AND LEAK CHECK OK. AREA CLEANED.