EDGE-CUTTING 6I8512 - Caterpillar

Hydraulic System
Illustration 1 g01035918
Diagram for the Oil Flow
(1) Oil flow to the implement cylinders
(2) Right side valve
(3) Steering metering pump
(4) Steering accumulator (If equipped)
(5) Combination valve
(6) Steering hydraulic pump
(7) Implement pump
(8) Signal lines for the implement valve
(9) Steering signal lines
(10) Pump control valve
(11) Hydraulic Tank
(12) Hydraulic tank filter
(13) Left side valve
(14) Oil flow to the relief valve for the steering consoleWhen the machine is started, the pump drive shaft begins to rotate. Hydraulic oil is pulled from hydraulic tank (11) by hydraulic pump (6) and (7). With no demand from the implement cylinders or the steering cylinders, the hydraulic pump is at low-pressure standby. The correct amount of oil is pumped to replace the internal leakage. Pump control valve (10) limits the oil pressure of the system. Steering pump (6) delivers pressurized oil to combination valve (5). The combination valve directs pressurized oil to both steering metering pump (3), to right valve group (2) and to left valve group (13).Steering metering pump (3) and right valve group (2) and left valve group (13) have individual signal lines to combination valve (5). From the combination valve, a resolved signal is directed to pump control valve (10). The resolved signal directs the hydraulic pump to meet the system loads.Hydraulic System Components
Illustration 2 g00546481
Pump Lines
(5) Combination valve
(6) Steering hydraulic pump
(7) Implement hydraulic pump
(10) Pump control valve
(11) Hydraulic tankSteering System
Illustration 3 g06186895
(15) Steering cylinders
(16) Steering crossover relief valve
(17) Steering priority valve
(3) Steering metering pump
(5) Combination valve
(6) Hydraulic pumps
(8) Hydraulic tank
(4) Steering accumulator (If equipped)
Illustration 4 g06186905
Component Location for the Steering System
(15) Steering cylinders
(16) Steering crossover relief valve
(3) Steering metering pump
(5) Combination valve
(6) Hydraulic pumps
(4) Steering accumulator (If equipped)The steering circuit is composed of the following main components:
Steering priority valve that is located in combination valve (5)
Steering relief valve that is located in combination valve (5)
Steering metering pump (3)
Steering crossover relief valve (16)
Left and right steering cylinders (15)
Steering accumulator (4) (If equipped)Hydraulic oil for the steering circuit is supplied by steering hydraulic pump (6). Steering priority valve (17) allows the steering to have priority over the implement circuit. The priority valve senses the pressure in the steering system. The priority valve directs the necessary flow demands to the steering system until the demand is satisfied.The pump flow is normally greater than required, so oil will flow to other implement circuits uninterrupted when the steering is operated. Steering metering pump (3) provides oil flow to steering cylinders (15). Steering cylinders (15) which are mounted on the front axle turn the front wheels to the right or to the left.Steering crossover relief valve (16) is located under the frame near the front of the machine. The steering crossover relief valve protects the steering system from external forces that may act on the wheels.