MAINTENANCE 4.12 EVERY 1000 OPERATING HOURS OR EVERY 6 MONTH High-Strength Bolt Connections (continued) Check fastening and condition of hydraulic oil cooler, illust. Z 21673 Reference No.: Qty. (1) 4 (2) 4 * SW = Wrench size 377 Bolt size mm Grade SW * mm Tightening torque Nm M30 10.9 46 1770 M30 10.9 46 1770