ENGINE AR-COMPLETE 1399906 - Caterpillar

Illustration 1 g03817181
Hydraulic System Schematic (1) Blade control valve (2) Pressure tap TP10 (3) Blade cylinder (4) Outlet line (5) Supply inlet line (6) Main relief valve (7) Makeup valve (8) Control spoolThe above illustration shows the blade control lever in the HOLD position.Supply oil from the steering pump is directed through supply inlet line (5) of blade control valve (1). Flow to the blade cylinder is blocked at control spool (8). In this case, the blade is held in position. At the same time, supply oil is directed through a passage in the control spool to outlet line (4). This oil is directed to the charge filter inlet.
Illustration 2 g03817183
Hydraulic System Schematic (1) Blade control valve (2) Pressure tap TP10 (3) Blade cylinder (4) Outlet line (5) Supply inlet line (6) Main relief valve (7) Makeup valve (8) Control spoolThe above illustration shows the blade control lever in the RAISE position.When the blade control lever is in the RAISE position, control spool (8) shifts. In this case, supply oil is directed to the rod end of the blade cylinder (3). Reduced pressure oil from the head end of the cylinder is returned through the control spool and directed to outlet line (4) .Main relief valve (6) maintains the differential pressure available to the blade system while allowing the excess pump flow to enter the charge circuit. The main relief valve is set at 8270 kPa (1199 psi) delta pressure (inlet to outlet). The pressure measured at pressure tap "TP10" (2) is 1100 600 kPa (159 87 psi)
Illustration 3 g03817187
Hydraulic System Schematic (1) Blade control valve (2) Pressure tap TP10 (3) Blade cylinder (4) Outlet line (5) Supply inlet line (6) Main relief valve (7) Makeup valve (8) Control spoolThe above illustration shows the blade control lever in the LOWER position.When the blade control lever is in the LOWER position, blade control spool (8) shifts to the right. In this case, supply oil is directed to the head end of the blade cylinder (3). Oil from the rod end of the cylinder is returned through the control spool and directed to outlet line (4).
Illustration 4 g03817188
Hydraulic System Schematic (1) Blade control valve (2) Pressure tap TP10 (3) Blade cylinder (4) Outlet line (5) Supply inlet line (6) Main relief valve (7) Makeup valve (8) Control spoolThe above illustration shows the blade control lever in the FLOAT position.When the blade control lever is in the FLOAT position, blade control spool (8) shifts into the detent position. In this case, the control spool opens a passage for oil to flow to the charge filter through outlet line (4). In the FLOAT position, control spool (8) also opens a passage between the rod end and the head end of blade cylinder (3). In this case, the blade is lowered under slight pressure until the blade contacts the ground. The pressure in the head end of the blade cylinder and the pressure in the rod end of the cylinder is equal. The effective area