Lesson 4/Learning Event 1
Although the screen in the oil pump pickup in the sump will strain out much of the dirt and carbon, it cannot
remove fine particles of dust and other abrasive materials that gather in the oil. An oil filter is used in the
lubrication system to remove all the abrasive materials possible. The oil filter is connected in the lubrication
system in one of two different ways, full flow or bypass.
FIGURE 61. FULL-FLOW FILTER SYSTEM.
In the full-flow system all the oil from the pump is sent through the filter before being routed through the
main oil line to the parts to be lubricated.
Let's trace the flow of the oil in the system. The oil is drawn from the sump through the pickup screen to the
pump. There the oil is pressurized and sent through the discharge side of the pump to the oil filter. Notice the
location of the pressure relief valve in the drawing. Notice, too, that oil getting through the relief valve is
returned to the sump.