What was found
CREW REPORTED, DURING CRUISE CONFIGURATION, HYDRAULIC PRESSURE LIGHT ILLUMINATED, FOLLOWED BY WHAT APPEARED TO BE SMOKE COMING FROM UNDER THE INSTRUMENT PANEL. FOLLOWED CHECKLIST TO ALLEVIATE SMOKE FROM CABIN. DIVERTED TO CLOSEST AIRPORT. LANDED WITHOUT INCIDENT. MX INSPECTED ACFT, FOUND HYD RESERVOIR SIGHT TUBE RUPTURED, AND RESERVOIR EMPTY. NO EVIDENCE OF SMOKE OR FIRE WAS FOUND. WHAT WAS THOUGHT TO BE SMOKE BY THE CREW WAS ATOMIZED HYD FLUID FROM RUPTURED SIGHT TUBE. MX REMOVED AND REPLACED SIGHT TUBE, SERVICED RESERVOIR, AND RELEASED ACFT BACK TO SERVICE.