TERMINAL 5454638 - Caterpillar

Illustration 1 g03381417
Hydraulic cooling fan (1) Inlet for hot oil (2) Fan speed solenoid (3) Fan directional solenoid (4) Hydraulic fan pressure sensor (5) Oil from cooling fan pump (6) Outlet for cool oil (7) Return oilThe hydraulic cooling fan is designed to maintain a proper operating range for the hydraulic fluid used in the subsystems of the machine. The hydraulic tank is connected to a vane pump that delivers 23 L/min (6 US gpm) to the cooling system. The fan begins to cool the hydraulic fluid when the oil in the reservoir reaches 54° C (130° F). The fan runs at maximum speed of 220 rpm when the oil in the reservoir reaches 71° C (160° F). When the oil reaches 82° C (180° F), the machine begins to de-rate to prevent damage to the hydraulic system.The cooling fan is controlled by the IQAN monitoring system. Solenoids are located on the fan to vary the speed of the fan. If the electrical input is removed from the forward/reverse control solenoid, the fan direction defaults to forward. If the electrical input is interrupted to the speed solenoid, the fan speed defaults to MAX. A pressure sensor on the fan and a temperature sensor at the hydraulic tank provide input to the IQAN system. Note: The IQAN system is programmed to reverse the direction of the fan every 30 minutes. The fan is reversed for 20 seconds to purge debris that builds up in the coils of the cooling block.A relief valve is mounted on the cooling fan hydraulic motor. The relief valve is set to 17926 kPa (2600 psi).
Illustration 2 g03381419
Rear back pressure manifold (anti-cavitation) (1) Inlet for hot oil (8) Relief settingThe rear back pressure manifold is mounted on the oil cooler and attached to the return filter tube of the cooling fan.One purpose of the return oil is to generate an "Anti-Cavitation" oil supply for the main hydraulic system. The back pressure manifold for anti-cavitation maintains positive pressure using the back-pressure that is generated on the return flow. The return oil flow is regenerated from all machine functions. The pressure setting for the manifold on the return filter tube (front back pressure manifold) is 827 kPa (120 psi). A second manifold is installed on the oil cooler inlet (rear back pressure manifold). The pressure setting for this manifold is 552 kPa (80 psi). Setting this manifold lower ensures full return flow through the oil cooler.