PLATE-WARNING-ROPS/FOPS 1311810 - Caterpillar

Return Hydraulic System
Hydraulic oil from pump 1 and pump 2 enters the main control valve. The oil then flows to the hydraulic tank in one of the following manners.When all joysticks and/or travel levers/pedals are in the NEUTRAL position, pump low-pressure standby oil from the hydraulic pumps flows through the center bypass passage in the main control valve. From the center bypass passage, the oil flows through the slow return check valve, hydraulic oil cooler, and returns back to the hydraulic tank.When any one of the joysticks and/or travel levers/pedals is shifted from the NEUTRAL position, center bypass passages in the main control valve are blocked. The return oil flows from the cylinders and/or motors back through the main control valve. The oil then flows through the slow return check valve to the hydraulic oil cooler, and returns to the hydraulic tank.Components of the return system include:
Return check valve
Bypass check valve
Hydraulic oil cooler
Hydraulic tank and filtersNote: Refer to the appropriate sections in this manual for more information.