BODY AS-PISTON 2803213 - Caterpillar

Illustration 1 g00949346
Schematic of the Main Hydraulic System (1) Pendulum arm control valve (2) Swing brake control valve (3) Pressure tap "PX" (4) Implement pump (5) Implement control valve (6) Pressure reducing valve (7) Steering cylinders (8) Swing motors (9) Hydraulic oil cooler bypass valve (10) Hydraulic oil cooler (11) Case drain filter (12) Crossover relief valve (13) Boom cylinders (14) Stick cylinder (15) Rotator (16) Hydraulic oil tank (17) Return filters (18) Extendable stick cylinder (A) Pressure oil to harvester head or work tool (B) Drain oil from harvester head or work tool (C) Return line from harvester head or work tool (AA) Implement pressure (BB) Return pressure (CC) Case drain (DD) Suction oilOil is drawn from hydraulic oil tank (16) by implement pump (4). The implement pump supplies pressurized oil to the following components: pendulum arm control valve (1), implement control valve (5), swing brake control valve (2), pressure reducing valve (6) and harvester head. The implement pump is a variable displacement axial piston pump. The pump allows constant load sensing pressure.
Illustration 2 g00956806
(3) Pressure tap.Note: The pressure of the oil from the implement pump can be measured with pressure tap (3). The pressure tap is located at the inlet section of the implement control valve on the "PX" port.Pendulum arm control valve (1) controls the flows of pressure oil to the pendulum arm cylinders.Reference: See Systems Operation, "Pendulum Hydraulic System" for the machine that is being serviced.The implement control valve controls the flow of pressure oil to steering cylinders (7), swing motors (8), boom cylinders (13), stick cylinder (14), rotator (15), and extendable stick cylinder (18). The valve spools in the implement control valve are closed center valves. No pressure oil will flow to the components, unless the valve spools are moved.After the oil flows through the implement control valve or the harvester head, the oil returns to hydraulic oil cooler (10). The cooler reduces the temperature of the oil before entering the hydraulic oil tank.When the temperature of the oil is low, the oil will not flow through the hydraulic oil cooler easily. When the temperature of the oil in the hydraulic system falls below a preset level, bypass valve (9) opens. The oil flows directly to the tank. All return oil is filtered by return filters (17) before entering the tank.Some oil that flows through the implement pump, swing motors, and motors on the harvester head leaks into the case. The oil is used to cool the pump or the motor. The oil also flushes debris from the pump or the motors. The oil is filtered by case drain filter (11) before entering the tank.