4) WHEN THE RCV LEVER IS IN THE DUMP POSITION Steering unit P port Steering unit LS port SX 3 P Pst T Regeneration check valve b1 b3 b2 4 B.D/F B.U CRAWD DUMP 1 3 4 2 P T 1.1 2.1 A1 7 P1 T Cut off valve P1 port Return line 24 X1 PS Return line 1 18 B1 E/G L L1 S1 17 74096WE06 В If the RCV lever (4) is pushed right, the bucket spool is moved to dump position by pilot oil pressure from port 2 of RCV. The oil from main pump (1) flows into main control valve (3) and then goes to the small chamber of bucket cylinder (9) by pushing the load check valve of the bucket spool. The oil at the large chamber of bucket cylinder (9) returns to hydraulic tank (17). When this happens, the bucket is dumped.
When the dumping speed of bucket is faster, the oil returned from the large chamber of bucket cylinder combines with the oil from the pump, and flows into the small chamber of the cylinder. This prevents cylinder cavitation by the negative pressure when the pump flow cannot match the bucket dump speed. В В В В 6-8 8 LH A2 ( ) ( ) Dump )( Floating Down ) ( Rollback Up Up