8. COMBINED BUCKET AND TRAVEL OPERATION ARM CYLINDER BUCKET CYLINDER BOOM CYLINDER SWING MOTOR TRAVEL MOTOR pc1 pa5 (34,2) B pa9 pb8 (34,1) P2 A pa11 pa8 TURNING JOINT pc7 A7 B7 pc2 pb3 pb7 pa3 pa7 B6 pc6 A6 P2 PH PA PP PS SH PT PS P1 A1 A2 FRONT PUMP REAR PUMP PILOT PUMP HYDRAULIC TANK 900L3HC27 When the bucket and travel functions are operated simultaneously, the bucket spool and travel spools in the main control valve are moved to the functional position by the pilot oil pressure from the remote control valve, and the straight travel spool is pushed to the right by the oil pressure from pilot pump.
The oil from the A1 pump flows into the travel motors through the LH travel spool of the left control valve and the RH travel spool of the right control valve via the straight travel spool of the control valve. The oil from the A2 pump flows into the bucket cylinder through the bucket spool via the confluence oil passage. The bucket is operated and the machine travels straight. 3-29 ps1 pa11 DR1 pc1 5 5 pb9 b5 1 1 1 pa PO B4 A4 B1 A1 DR pc7 A3 B3 pb3 ARM1 5 OPTION 7 pb9 ARM2 B8 A8 BUCKET DR2 pc2 p BOOM2 SWING TRAVEL-LH