COVER-WATER PUMP 8N5179 - Caterpillar

Left-Hand Steering and Transmission Control
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(34) Speed range upshift and downshift
(35) Transmission forward, neutral, and reverse
(36) Left steering
(37) Right steeringThe left-hand steering and transmission control combines the steering functions and the transmission functions for the machine. Move the control to the left or to the right to articulate the machine.The transmission direction switch (35) is located on the front of the control. The speed range thumb roller (34) is located near the top of the steering and transmission control.For more information on left-hand steering and transmission control refer to Systems Operation, "Steering Control (Control Systems)".Steering Pump
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Left side view of machine
(22) Steering pumpThe steering pump (22) is located on the left side of the machine mounted to left-side pump drive gears. The variable displacement piston pump senses both pressure and flow requirements for the system. The steering pump draws oil from the hydraulic tank and sends flow through the supply hose to the steering control valve. The pump compensator valve controls pump flow and maximum system pressure.Steering Valve Operation
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(2) Steering primary pilot ON OFF solenoid
(7) Steering valve
(12) Left secondary steering solenoid
(13) Right secondary steering solenoid
(14) Left primary steering solenoid
(15) Right primary steering solenoid
(30) Directional control spool position sensor
(39) Main steering relief valve
(40) Back-up relief valve
(41) Steering workport relief valveThe steering control valve (7) is mounted to the front of the transmission near the articulation hitch. Directional steering control is accomplished by the actuation of the machines articulation cylinders by the steering valve. The implement ECM is the primary control of the steering valve with the transmission ECM being the secondary or backup in case of failure. For more information on implement ECM and power train ECM control refer to Systems Operation, "Steering Control (Control Systems)".Spool Position Signal
The implement ECM receives input from the spool position sensor (30) of the steering valve (7) to indicate the position of the steering valve spool. The ECM uses this information to help determine if the spool of the steering valve is responding correctly to the steering control signal. For more information on the spool position sensor refer to Systems Operation, "Steering Control (Control Systems)".Steering Cylinders
The steering cylinders (5) are located on the sides of the machine. The steering cylinders have an internal position sensor. These sensors allow the implement ECM and the transmission ECM to monitor the steering position of the steering cylinders. This signal is compared to the position of the left-hand steering control sensor for diagnostic purposes. For more information on the left-hand steering control sensor, refer to Systems Operation, "Steering Control (Control Systems)".Steering Cylinder Position Sensors
The position sensors (33) of the steering cylinder are mounted on the head end of the articulation cylinders. The position sensor provides a PWM input signal to the implement ECM and to the machine control ECM. The left sensor is powered from the transmission ECM. The right sensor is powered from the implement ECM. For more information on the steering cylinder position sensors, refer to Systems Operation, "Steering Control (Control Systems)".Pilot Steering Accumulator
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