HOSE A 0909569 - Caterpillar

Illustration 1 g00474335
Rear of hydraulic tank (return circuit) (1) Return filter (2) Hydraulic tank (3) Return line
Illustration 2 g00474336
Bypass check valve (3) Return line (4) Return line (5) Inlet line from oil cooler (6) Bypass check valve (7) Outlet line from oil cooler to hydraulic tank (8) BlockThe oil flows through return line (4) to inlet line (5). The oil then flows from inlet line (5) to bypass check valve (6) . When the return oil temperature is very low, resistance to the oil flow in return line (4) is high. The resistance to the flow causes an increase in the oil pressure. Bypass check valve (6) opens when the oil pressure increases. Most of the return oil flows through bypass check valve (6), return line (3) and return filter (1) to hydraulic tank (2). The remaining oil flows through inlet line (5) to the oil cooler. Directing more of the oil flow to hydraulic tank (2) causes the oil temperature to increase. Increased oil temperature assists in minimizing the pressure loss and smoothing the movement of hydraulic components.When the oil temperature increases, the oil pressure decreases. Bypass check valve (6) begins to close. When bypass check valve (6) closes more oil flows through inlet line (5) to the oil cooler which maintains optimum oil temperature.