1) WHEN THE RCV LEVER IS IN THE RAISE POSITION WHEN THE RCV LEVER IS IN THE RAISE POSITION 40 S1 S2 7609FWE03 В When the RCV lever (4, boom) is pulled back, the boom spool is moved to raise position by pilot oil pressure from EH control block (40). The oil from main pump (1) flows into main control valve (3) and then goes to the large chamber of boom cylinder (12). The oil from the small chamber of boom cylinder (12) returns to hydraulic oil tank (21) through the boom spool at the same time. When this happens, the boom goes up.
В В В 6-4 13 12 28 PS RH 28 PS a2 a3 LS 3 T P a1 A1 B1 A2 B2 pst A3 B3 Floating Aux Bucket Boom 4 Joystick Dump Down 5 9 Control unit Bucket Aux back (Electro-Hydraulic & Joysick steering) Boom Roll Up EH18 EH17 EH20 EH19 EH22 EH21 T P 4 1 6(4) 3(2) 5(3) 2(1) ( ) : 2 Spool b1 A2 B2 To MCV b2 LH b3 12 a3 b3 a1 b1 a2 b2 41 A1 Steering valve 27 27 10 (EHPS) EF port Steering valve (EHPS) LS port S1 X1 X2 P1 T 11 X3 Return line 28PS1 X1 X2 22 Return line ring system 23 B1 B2 24 25 21 S1 L2 L1 S2 L4L3 Fan & brake pump 3 12 28 PS RH 28 PS a3 LS A3 B3 a2 1 B1 A2 B2 pst Dump Floating Down Bucket back Roll Up Boom Aux