4. COMBINED SWING AND BUCKET OPERATION ARM CYLINDER BUCKET CYLINDER BOOM CYLINDER SWING MOTOR TRAVEL MOTOR pc1 (34,2) pa9 pa5 (34,1) P2 pa11 pb8 pa8 TURNING JOINT A7 B7 pc2 pb3 pb7 pa3 pa7 pc7 pc6 A6 B6 PT PS P1 P2 PH PA PP PS SH A1 A2 FRONT PUMP REAR PUMP PILOT PUMP HYDRAULIC TANK 900L3HC23 When the swing and bucket functions are operated simultaneously, the swing spool and bucket spool 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 the swing spool in the left control valve.
The oil from the A2 pump flows into the bucket cylinder through the bucket spool in the right control valve. The upper structure swings and the bucket is operated. 3-25 ps1 pa11 DR1 pc1 B5 A5 pb9 pb5 1 1 1 pa P B A B B1 A A1 DR pc A3 B3 pb ARM1 5 O 4 4 OPTION 7 7 3 pb9 ARM2 B8 A8 BUCKET DR2 pc2 p 3 BOOM2 2 SWING 3 2 6 11 TRAVEL-LH