8. TRAVEL FORWARD AND RE 8.
TRAVEL FORWARD AND RE VERSE O VERSE O PERATION PERATION SWING MOTOR ARM CYLINDER BUCKET CYLINDER BOOM CYLINDER ps1 ps2 T3 T1 T2 T4 pa10 B9 RH TRAVEL MOTOR LH A9 ARM 2 pb9 MB Dr REG Ps MA MB Ps REG Dr MA pa9 B8 pb8 A8 BUCKET DR2 pa8 DR2' VA(BW) VB(FW) VA(FW) VB(BW) pc2 B7 A7 A B D G F E BOOM 1 DR4 pb7 pc7 C pa7 pb6 A6 B6 pa6 TRAVEL P T P3 P2 PH PA PP PT P1 PS PS (2) (1) (4) (3) pb6 pa1 pb1 pa6 BOOM P T BUCKET ARM P T SWING T1 T2 PUMP A1 PUMP A2 PILOT PUMP (2) (1) (3) (4) (2) (3) (1) (4) P T T3 dr# A D E F G H J B TRAVEL SPEED SOLENOID VALVE PH (MCV) F (T/JOINT) a b d e f g h j c h1 j1 d1 f1 g1 e2 A1 A2 A5 P3 P4 Pi(D/C VALVE) PP(MCV) pa2 pb2 PS P pb9 pb5 T PS PS PS PS PS PS A B C P2 P(2-EPPR) Td# HYDRAULIC TANK pa9 pc1 pa5 pa8 pa11 pb8 pc2 pa7 pa3 (Td#) P1 LINE FILTER pc6 pb3 pb7 480A3HC18 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 (pa1, pb1, pa6, pb6) 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. 3-22 3-22 A5 pb5 ARM 1 pa5 B4 A4 pb4 pa4 OPTION TRAVEL(LH TRAVEL STRAIGHT CROSS ASS P1 P2 P3