8.
TRAVEL FORWARD AND REVERSE OPERATION ARM CYLINDER BUCKET CYLINDER BOOM CYLINDER SWING MOTOR TRAVEL MOTOR pc7 pc2 A7 pa3 pb3 A3 B3 BOOM2 B7 pc2 pb3 pb7 pc7 TURNING JOINT A2 B2 DR3 pb2 SWING BOOM1 pa3 pa7 A6 B6 B1 pc6 pa2 TRAVEL-RH pb6 pa6 pc6 A1 pa1 pb1 TRAVEL-LH STRAIGHT TRAVEL RCV PEDAL P T TRAVEL pr1 P3 PT PS P1 P2 PH PA PP PS SH pa6 pb6 pb1 pa1 (4) (1) (2) (3) SWING ARM BUCKET BOOM P T P T Dr#, dr# A1 A2 TRAVEL SPEED SOLENOID VALVE FRONT PUMP REAR PUMP PILOT PUMP Pk (T/Joint) PH (MCV) (4) (1) (2) (3) a b d e f g h j c d1 h1 PS PS PS (4) (1) (2) (3) A5 A1 A2 A3 P4 PG (S/Motor) pb5 pa2 pb2 pa9 pb8 pa8 pa7 pb7 h2 P3 P2 PP(MCV) HYDRAULIC TANK RELIEF VALVE T(dr1) P1 LINE FILTER 900L3HC18 When the travel levers are pushed forward or reverse position, the travel spools in the main control valve are moved to the forward or reverse travel position by the pilot oil pressure from the remote control valve.
The oil from the each pump flows into the main control valve and then goes to the each travel motor through the turning joint. The return oil from both travel motors returns to the hydraulic oil tank through the turning joint and the travel spools in the main control valve. When this happens, the machine moves to the forward or reverse. 3-20 ps1 T3 T1 T2 T4 ps2 pa11 pa10 DR1 pc1 B5 A5 B9 pb9 pb5 A9 ARM1 pa5 ARM2 pb9 pc1 PO pa5 B4 B8 pa9 (34,2) A4 A8 P2 B A AB 11 OPTION BUCKET pp ab 18 1 (34,1) pa8