5) WHEN THE RCV LEVER IS IN THE ROLL BACK (retract) POSITION 14 13 4 Aux Bucket 5 Control unit EH18 EH17 EH20 EH19 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 757F6WE07 В If the RCV lever (4, bucket) is pulled left, the bucket spool is moved to roll back position by pilot oil pressure from EH control block (6). The oil from main pump (1) flows into main control valve (3) and then goes to the large chamber of bucket cylinder by pushing the load check valve of the bucket spool. The oil at the chamber of bucket cylinder (14) returns to hydraulic tank (22). When this happens, the bucket roll back.
В В В 6-9 LH RH 29 PS PS 29 40 a1 a2 a3 P A1 B1 A2 B2 A3 B3 3 Floating LS Boom Bucket Boom Aux Dump Down Joystick 4' Pst Up back ick steering) T Roll 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 11 X3 9PS 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 Down Boom Aux Roll back Up Up