3) WHEN THE RCV LEVER IS IN THE FLOAT POSITION 14 13 4 Aux Bucket 5 Control unit EH18 EH17 EH20 EH19 EHCU 6 4 1 6(4) 3(2) a3 b3 a1 b1 a2 b2 Steering valve (EHPS) EF port Steering valve (EHPS) LS port Return line Steering system 757F6WE05 В When the RCV lever (4, boom) is pushed further forward from the lower position, the pilot pressure reaches to 13~15bar, then the boom spool is moved to floating position. The work ports (A2), (B2) and the small chamber and the large chamber are connected to the return passage, so the boom will be lowered due to it's own weight.
In this condition, when the bucket is in contact with the ground, it can be move up and down in accordance with the shape of the ground. В В 6-7 LH RH 29 PS PS 29 40 a1 a2 a3 P A1 B1 A2 B2 A3 B3 3 Floating LS Boom Dump Bucket Boom Aux Joystick Down 4' Pst back Roll Up ick steering) T H22 EH21 T P 5(3) 2(1) ( ) : 2 Spool To MCV b1 b2 b3 A1 28 28 11 12 S1 X1 X2 P1 T X3 9PS1 X1 X2 23 Return line B1 B2 24 25 26 22 S1 L2 L1 S2 L4L3 Fan & brake pump LH 40 a1 a2 A1 B1 A2 LH RH 29 PS PS 29 a3 B2 A3 B3 Dump Bucket Floating Boom Aux Roll back Down Up Down Up