TURBOCHARGER GP 3918890 - Caterpillar

Illustration 1 g01433877
(1) Filter element (2) Tank chamber (3) Relief valve (4) Return line (5) Return chamber (6) Suction filter (7) Suction portThe return oil from return line (4) enters return chamber (5) in the hydraulic tank. The return oil then flows through filter element (1) to tank chamber (2). Contaminants are removed by the filter element. The oil in the tank chamber flows through suction filter (6) and the oil flows through suction port (7) to the pumps. When filter element (1) is clogged with contaminants, relief valve (3) opens in order to allow the return oil to bypass the filter element.
Illustration 2 g01433878
(8) Air breatherAir breather (8) is located on the upper surface of the hydraulic tank. The air breather prevents an increase or a decrease of air pressure in the hydraulic tank regardless of the following circumstances :
Change of air pressure in the hydraulic tank due to cylinder movement.
Change of air pressure in the hydraulic tank capacity due to a temperature change.