HOSE-RADIATOR INLET 8N3246 - Caterpillar

Illustration 9 g00481924
Makeup Valve (1) Passage to Cylinder Head End (2) Drain Passage (3) Spring (A) Normal Operation (B) Makeup Operation (CC) Oil Flow to Cylinder (DD) Tank or Makeup OilMakeup valves are located in the control valve sections for bulldozer lift and ripper lift. The makeup valves are in the passages to the head end of the bulldozer lift and ripper cylinders.When there is pressure in the head end of the bulldozer lift and ripper cylinders, the makeup valve is held closed. However, when the blade or the ripper is lowered rapidly, the pressure in drain passage (2) is greater than the pressure in head end passage (1) . Pressure from the drain passage is felt in the cavity of the makeup valve. The pressure moves the valve to the left. Spring (3) is compressed. Drain oil can now flow into the head end of the cylinders.Bulldozer Angle Valve
HOLD Position
Illustration 10 g00483060
Bulldozer Angle Valve (HOLD Position) (A) ANGLE RIGHT Position (B) HOLD Position (C) ANGLE LEFT Position (1) Makeup and Relief Valve (2) Port to Rod End of Right Cylinder and Head End of Left Cylinder (3) Port to Rod End of Left Cylinder and Head End of Right Cylinder (4) Main Control Spool (5) Passage to Tank (6) Signal Passage to Primary Resolver (7) Spool (8) Holes (9) Pump Passage (10) Passage (11) Spring (12) Signal Cavity (13) Signal Port (14) Signal Passage to Primary Resolver (15) Passage to Tank (16) Spring (AA) Pump Oil Pressure (HH) Blocked Oil (LL) Return Oil PressureThe bulldozer angle control valve is located between the control valve section for ripper lift and the control valve section for tilt. The valve section for bulldozer angle control is located between the end cover and the control valve section for tilt, on machines without a ripper.Spring (16) on the end of valve spool (4) is compressed when the spool is moved to either angle position. The spring will move valve spool (4) and the control lever to the HOLD position when the control lever is released.Pump oil from the control valve section for tilt enters the valve section for bulldozer angle control through passage (9) . Passage (9) is a common passage through all of the valve sections. Passage (9) has no outlet. The pump oil goes through holes (8) into spool (7) . This causes the spool to move down against the combined signal pressure from port (13) and the force of spring (11) in cavity (12) . When holes (8) start to close off pump passage (9) , a restriction is created. This restriction limits pressure inside spool (7) to 415 kPa (60.2 psi) more than the pressure in signal cavity (12) .HOLD PositionIn the HOLD position, spool (4) stops pressure oil in passage (10) from going into ports (2) and (3) . The oil in port (3) is blocked. The oil in port (2) is