The diesel filter is mainly used to remove a small part of the water vapor in the diesel oil tank and mechanical impurities in the diesel oil. It is used to filter diesel oil. The setting methods of maintenance parts for excavators of different brands and tonnage are quite different. If the fuel delivery pipeline is used, the diesel oil comes out of the diesel oil tank first through the oil-water separator, then through the diesel oil primary filter and diesel oil secondary filter, and finally into the high-pressure fuel pump.

The primary diesel filter is close to the fuel transfer pump, while the secondary diesel filter is closer to the diesel pump. However, on some excavators, the diesel filter and fuel water separator are integrated, which can filter the water and mechanical impurities in the diesel. Some excavators have only one diesel filter, and there is no distinction between the primary filter and the secondary filter.

Replacement method of diesel filter element
Close the inlet ball valve and open the upper cover. For the aluminum alloy upper cover, gently pry it from the side gap with a flat head screwdriver to unscrew the drain plug, drain the dirty oil, loosen the fastening nut on the top of the filter element, wear oil proof gloves, hold the filter element, and vertically remove the old filter element.
Replace the filter element with a new one, pad the upper sealing ring, and the lower end has its own sealing gasket. Tighten the nut, tighten the drain plug, and cover the upper end cap. Pay attention to pad the sealing ring, and install the fastening bolt.