What was found
CREW REPORTED LOW QUANTITY WITH GREEN HYDRAULIC SYSTEM. CREW, SAMC, DISPATCH AGREED TO DIVERT TO ORD. AMBER ALERT DECLARED, EQUIPMENT REQUESTED TO MEET AIRCRAFT IN ORD. *S/D* FOUND NR 1 ENGINE HYDRAULIC PRESSURE SWITCH BACKED OUT AND THE O-RING DISPLACED. REPLACED THE O-RING AND SECURED THE SWITCH TO PROPER TORQUE. LEAK CHECKS GOOD ON ENGINE RUN.