As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LANDED UNDER AMBER ALERT DUE TO LOSS OF NR 4 HYDRAULIC SYSTEM PRESSURE. NORMAL LANDING AND TAXI TO GATE. [07-27-07] AFTER EXTENSIVE TROUBLE-SHOOTING, REPLACED NR 4 HYDRAULIC QUANTITY TRANSMITTER, PER FIM 29-30. SERVICED HYD TO FULL. AIRCRAFT RETURNED TO SERVICE.