2. COMBINED SWING AND BOOM UP OPERATION ARM CYLINDER BUCKET CYLINDER BOOM CYLINDER SWING MOTOR TRAVEL MOTOR pc1 pa5 (34,2) pb8 (34,1) P2 pa11 TURNING JOINT A7 B7 pc2 pc7 pb3 pb7 pa3 pa7 B6 pc6 A6 PT PS P1 P2 PH PA PP PS SH A1 A2 FRONT PUMP REAR PUMP PILOT PUMP HYDRAULIC TANK 900L3HC21 When the swing and boom up functions are operated simultaneously, the swing spool and boom spools in the main control valve are moved to the functional position by the pilot oil pressure from the remote control valve. The oil from the A1 pump flows into the swing motor through swing spool and the boom cylinder through boom 2 spool.
The oil from the A2 pump flows into the boom cylinders through the boom 1 spool in the right control valve. The upper structure swings and the boom is operated. Refer to page 3-8 for the boom priority system. 3-23 ps1 pa11 DR1 pc1 B5 A5 pb9 pb5 ARM1 pa5 PO B4 A4 B B1 OPTION A A1 DR7 pc7 A3 B3 pb3 pb9 ARM2 B8 A8 BUCKET DR2 pc2 p