MAINTENANCE 4.12 EVERY 1000 OPERATING HOURS OR EVERY 6 MONTH High-Strength Bolt Connections (continued) Check fastening and condition of control valve carrier, main control valves (I, II and III) and swing control valve (5), illust. Z 21777 Reference No.: Qty. (1) 4 (2) 3 (3) 9 (4) 3 (5) Swing control valve * SW = Wrench size 395 Bolt size mm Grade SW * mm Tightening torque Nm M24 10.9 36 880 M20 10.9 30 510 M20 10.9 30 510 M16 10.9 24 265