SLEEVE 1633127 - Caterpillar

Illustration 1 g06054560
Rear of Machine
(1) Hydraulic oil cooler
(2) Fuel coolerHydraulic oil cooler (1) is located at the rear of the machine. Fuel cooler (2) and the oil cooler are combined under a single housing. The engine compartment cover provides access to this component.Oil from port "TC" of the return manifold is directed into the inlet port of hydraulic oil cooler (1).
Illustration 2 g06054563
Right Side of Machine
(3) Return manifold
(4) Hydraulic oil temperature sensorReturn manifold (3) is located on the right side of the machine, behind the cab. A removable panel on the underside of the machine frame provides limited access to this component.The return manifold collects oil from the following locations:
Case drain of the axle section of the propel pump
Case drain of the drum section of the propel pump
Case drain of the axle motor
Case drain of the drum motor
Case drain of the vibratory motorOil from these locations is combined and directed to the thermal bypass valve which is located inside return manifold (3).The thermal bypass valve contains a wax pellet. The wax pellet expands as the hydraulic oil temperature increases. As the wax expands, the bypass spool moves. The bypass spool controls the oil flow through port "R" of the return manifold. This port is connected to the hydraulic tank. Oil flowing through this port bypasses the oil cooler.When the oil is cold, the oil flows directly to the tank through port "R" of the return manifold. When the hydraulic oil temperature reaches 54 °C (130 °F), the wax in the thermal bypass valve begins to expand. This action causes the spool to begin to close the passage to port "R" of the manifold. When the oil temperature reaches 66 °C (150 °F), the bypass spool is fully closed. In this case, the passage to port "R" of the manifold is fully closed. All the oil flow is sent through port "TC" of the manifold to the oil cooler.The thermal bypass valve also has a relief function. When the bypass is closed and hydraulic pressure reaches 345 kPa (50 psi), the pressure will unseat the valve poppet. Under these conditions, the oil can flow directly to the tank in order to lower the pressure. This relief function operates during spikes in case flow or in the event of cooler restrictions.Hydraulic oil temperature sensor (4) is installed in return manifold (3). This sensor provides input to the machine ECM. The ECM uses this input in the fan control logic and also in order to display the oil temperature.