SUPPORT AS 6C6220 - Caterpillar

Illustration 1 g06315692
Demand fan piston motor
(1) Piston motor (hydraulic fan)
(2) Case drain
Illustration 2 g06315697
Near zero fan speed control valve
(3) Near zero fan speed control solenoid
(4) Inlet hose from fan motor
(5) Orifice
(6) Return hose to tank
(7) Outlet hose to cooler bypass valve
Illustration 3 g06315729
Hydraulic oil cooler thermal bypass valve
(7) Outlet hose to cooler bypass valve
(8) Outlet hose to oil cooler
(9) Return hose from oil cooler
(10) Thermostatic control valve
(11) Return hose to hydraulic tank
(12) Thermal bypass valve
(13) Oil temperature sensor
Illustration 4 g06315748
(14) Hydraulic oil coolerOil from the piston motor (hydraulic fan) (1) enters the cooler system at hose (4).Flow will be directed to the near zero fan speed valve and the orifice (5). In normal operation the near zero fan speed valve will allow flow through and to the thermal bypass valve. In Near zero mode flow is sent through orifice (5) to hose (6) to the return filter and into the hydraulic tank. When the oil reaches a predetermined temperature, the ECM sends a signal to solenoid (3) oil flows out of hose (7) to thermal bypass valve (12). Thermal bypass valve (12) is open allowing flow both through the cooler (14) and hose (11). This flow will continue until the hydraulic temperature reaches 60° C (140° F). When the hydraulic temperature reaches 60° C (140° F), the bypass valve will close and force all the flow through the cooler.Temperature sensor (13) is monitored by the implement ECM. The ECM uses the signal from sensor (13) to control the displacement of the fan piston pump. The flow from the fan piston pump will control the speed of the demand fan.