HOUSING-RETARDER 1409958 - Caterpillar

Operation
When the hydraulic activation lever is moved to the UNLOCK position, pilot pump (31) supplies oil to solenoid valves: (5), (6), (14), (15), (16) and (17). When right joystick thumbwheel (36) is moved FORWARD, the machine ECM sends a signal to the extend solenoid for attachment control valve (14). The machine ECM also sends a signal to the solenoid for number one check valve "EC1" (13) in order to open the valve. The machine ECM also sends a signal to the solenoid for one-way flow and two-way flow "EC3" (7) in order to de-energize this valve. Pilot oil flows to the top of attachment control valve (21). The pilot oil will shift the spool to the DOWNWARD position. This allows oil from drive pump (30) to flow through attachment control valve (21). The pump oil flows through the line for the work tool (9) to the work tool. The working pressure for the work tool is limited by the line relief valve for the work tool (12) through number one check valve "EC1" (13).When right joystick thumbwheel (36) is moved BACKWARD , the machine ECM sends a signal to the retract solenoid for attachment control valve (15). The machine ECM sends a signal to the solenoid for number two check valve "EC2" (11) in order to open the valve. The machine ECM also sends a signal to the solenoid for one-way flow and two-way flow "EC3" (7) in order to de-energize this valve. Pilot oil flows to the bottom of attachment control valve (21). The pilot oil will shift the spool to the UPWARD position. This allows oil from drive pump (30) to flow through attachment control valve (21). The pump oil flows through the line for the work tool (8) to the work tool. The working pressure for the tool is limited by the line relief valve for the work tool (10), through number two check valve "EC2" (11).During operation of the work tool, the machine ECM sends a signal to the proportional solenoid valve for negative flow control (18). Negative flow control pressure in the center bypass passage is blocked when the control valve spools shift DOWNWARD. 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
Illustration 7 g01626912
Illustration 8 g01626916Description
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 17: Default