LUBRICATION GP-EQUALIZER BAR 3844040 - Caterpillar

One-Way/ One or Two Pump - Hydraulic control is designed to allow hydraulic control over the work tool. A One-Way/ One or Two Pump - Hydraulic control system combines the features of the one-way flow system with the features of the one pump/two pump flow system.One-Way Flow from One Pump
The one pump flow system allows flow from one pump to power a work tool. All of the load is placed on a single pump. One pump flow is used for work tools that require low flow rates for actuation.One-way flow from one pump can be achieved by selecting a work tool that requires one-way flow from one pump. The work tool can be selected through the monitor or by the work tool select switch. A typical example is a hammer that receives oil from one pump only. This operation also allows return oil to flow directly to the oil cooler instead of through the main control valve. This action will allow for a higher flow of oil with the reduction of resistance by bypassing the main control valve.When one pump flow is required to the work tool, the pump supplying the oil can be programmed through the monitor. The following situations are listed to increase controllability of the work tool.
When the work tool with a boom and bucket operation is used most often, the idler pump is recommended as the supply pump.
When the work tool with a stick and swing operation is used most often, the drive pump is recommended as the supply pump.Reference: Refer to Testing and Adjusting, "Work Tool Parameter - Program" for the tool control system to change the settings for work tool operation.Reference: Refer to Testing and Adjusting, "One-Way / One or Two Pumps - Hydraulic Control: Default Value of Work Tool Parameters" for the Tool Control System to reference the factory settings.
Table 1
Operation Lever List
Control Extension
Hydraulic Foot Pedal Push Forward
Illustration 2 g03885912
One-Way Flow from One Pump (drive pump)
(4) Proportional reducing valve (A1 extend)
(5) Hydraulic foot pedal (pilot valve)
(8) Relief valve
(10) Attachment 2 (F2 stack valve)
(12) Tool line relief valve
(13) Attachment 2 control valve (idler pump)
(18) Center bypass passage (drive pump)
(23) Attachment 1 control valve
(25) Negative flow control valve
(26) Negative flow control valve
(36) Hydraulic tank
(38) Idler pump
(39) Drive pump
(40) Pilot pump
(42) Proportional reducing valve (flow limit 1)
(43) Flow limit 1 pressure sensor
(45) Hammer return filter (if equipped) The following description is made under the assumption that the drive pump (39) is supplying oil to the work tool.When the device for activation listed in Table 1 is pressed, the machine ECM sends a modulated signal to proportional reducing valve (4). Proportional reducing valve (4) allows pilot oil to flow to attachment control valve (23). Attachment control valve (23) shifts, allowing high-pressure oil from the drive pump (39) to flow to the work tool.When abnormally high pressure occurs in the line, work tool relief valve (8) opens at the set pressure. This opening will allow the high-pressure oil into the return system and back to the hydraulic