BUSHING 4319196 - Caterpillar

Pilot pump (31) supplies oil to pilot manifold (28). When the hydraulic activation lever is moved to the UNLOCK position, pilot oil flows from pilot manifold (28) to the right pedal (3), left pedal (1), and the proportional solenoid valve for negative flow control (15).When right pedal (3) is pressed in the BACKWARD position, pilot oil is directed to the bottom of auxiliary control valve (23). The pilot oil will shift the spool in the auxiliary control valve to the UPWARD position. That allows oil from drive pump (29) to flow through auxiliary control valve (23). The pump oil flows through the line for the work tool (12) to the work tool. Return oil flows through the line for the work tool (13), through auxiliary control valve (23), and back to hydraulic tank (32). The working pressure for the work tool is regulated by line relief valve (22).During operation of the work tool, the machine ECM sends a signal to the proportional solenoid valve for negative flow control (15). Negative flow control pressure in the center bypass passage is blocked when the control valve spools shift UPWARD. The machine ECM has the following programmed parameter values: "A1 FLOW", "A1 MULTI ADD FLOW", "A1 NOMINAL PRES" and "COMBINER ENABLE". The parameters control the flow and pressure for the work tool. The machine ECM regulates the negative flow control pressure that will be supplied to the pump regulator. The negative flow control pressure forces the swashplate in the pump to the correct angle to limit the flow and pressure to the work tool.Two-Way Flow From Two Pumps
Description
The default parameter values for two-way hydraulic oil flow from two main pumps are shown in Table 1. A typical example is a pulverizer. Refer to Testing and Adjusting, "System 11: Default Value of Work Tool Parameters" for the Tool Control System.Use the display monitor or ET in order to set the hydraulic flow to the work tool.Operation
Illustration 7 g01537323Pilot pump (31) supplies oil to pilot manifold (28). When the hydraulic activation lever is moved to the UNLOCK position, pilot oil flows from pilot manifold (28) to the right pedal (3), left pedal (1), and the proportional solenoid valve for negative flow control (15).When right pedal (3) is pressed in the FORWARD position, pilot oil is directed to the top of auxiliary control valve (23) and to the top of attachment control valve (25). The pilot oil will shift the spools in the control valve to the DOWNWARD position. That allows oil from drive pump (29) to flow through auxiliary control valve (23) and oil from idler pump (30) to flow through attachment control valve (25). The two pump flow combines after leaving the control valves. The pump oil flows through the line for the work tool (13) to the work tool. Return oil flows through the line for the work tool (12), through auxiliary control valve (23), and back to hydraulic tank (32). The working pressure for the work tool is regulated by line