EDGE 7D4509 - Caterpillar

Hydraulic System
Illustration 1 g02022545
Fan hydraulic system
(1) Fan drive motor
(2) Makeup valve
(3) Fan drive pump
(4) Pump drive
(5) Pressure reducing valve (fan drive)
(6) Oil filter (case drain)
(7) Solenoid and relief valve
(8) Oil filter (steering and fan drive)
(9) Oil cooler (steering and fan drive)
(10) Hydraulic tank Location of Components
Illustration 2 g02022580
JSM1-168
Left side view of fan drive lines
(2) Makeup valve
(3) Fan drive pump
(4) Pump drive
(5) Pressure reducing valve (fan drive)
(6) Oil filters (case drain)
(7) Solenoid and relief valve
(10) Hydraulic tank
Illustration 3 g02022590
Rear view of fan drive lines
(1) Fan drive motor
(2) Makeup valve
(11) Radiator Operation
Oil flows from fan drive pump (3) through makeup valve (2) to fan drive motor (1). Oil flows from the motor through makeup valve (2). The oil flows from makeup valve (2) through oil filters (8) and oil cooler (9). The oil flows from oil cooler (9) to hydraulic tank (10) for the steering and fan drive.Fan drive motor (1) is a fixed displacement motor. The fan speed is determined by the amount of flow from fan drive pump (3). Fan drive pump (3) is a variable displacement piston pump that is controlled by the Brake/Cooling ECM.Case drain oil flows from fan drive motor (1) and fan drive pump (3) through oil filter (6) to the hydraulic tank.If the supply oil to the fan stops suddenly, the fan and the motor may continue to rotate because of the mass of the fan. Makeup valve (2) allows the oil in the circuit to flow from the return side to the supply side. The flow prevents a vacuum in the lines on the supply side.Pressure reducing valve (5) utilizes steering system pressure in order to keep the fan speed below 10 rpm in cold weather. The fan speed should never be 0 rpm.Fan speed is controlled by the Brake/Cooling ECM. Fan speed will vary depending on many inputs.The minimum fan speed will be below 10 rpm. The minimum fan speed will occur when all of the temperature inputs are cold.The following inputs determine the fan speed:
Jacket water coolant temperature
Aftercooler coolant temperature
Transmission lubrication temperature
Torque converter oil temperature
Brake oil temperature
Brake status
Ground speed
Output status of the hoist system
Table 1
Standard Fan Speed Control Limits (RPM)
106 Inch Fan
Engine Speed Non-Retarding Fan Speed Limit Retarding Fan Speed Limit
1250 or Less 339 525
1300 353 525
1450 394 525
1500 407 525
1600 434 525
1700 461 525
1750 or more 475 525 Refer to Table 1 for the fan speed limits that are based on the temperature sensor inputs, the ground speed, and the retarding/braking inputs.
Table 2
Engine Fan Control, Non-Retarding Or Retarding Below 4 MPH
106 Inch Fan(1)
Aftercooler Temperature Jacket Water Coolant Temperature Transmission Lubrication Temperature TC Out Temperature Brake Oil Temperature Fan Control
Priority 1 2 3 4 5
< 65 °C (149 °F) < 88 °C (190 °F) < 88 °C (190 °F) < 88 °C (190 °F) < 102 °C (215 °F) Off
< 65 °C (149 °F) < 99 °C (210 °F)
> 88 °C (190 °F) < 96 °C (204 °F)
> 88 °C (190 °F) < 102 °C (216 °F)
> 88 °C (190 °F) < 107