Oil Pickup and Strainer
The oil pickup is a tube that extends from the oil
pump to the bottom of the oil pan. One end of the pickup
tube bolts or screws into the oil pump or to the engine
block. The other end holds the strainer.
The strainer has a mesh screen suitable for straining
large particles from the oil and yet passes a sufficient
quantity of oil to the inlet side of the oil pump. The
strainer is located so all oil entering the pump from the
oil pan must flow through it. Some assemblies also
incorporate a safety valve that opens in the event the
strainers become clogged, thus bypassing oil to the
pump. Strainer assemblies may be either the floating or
the fixed type.
The floating strainer has a sealed air chamber, is
hinged to the oil pump inlet, and floats just below the top
of the oil. As the oil level changes, the floating intake
will rise or fall accordingly. This action allows all oil
taken into the pump to come from the surface This
design prevents the pump from drawing oil from the
bottom of the oil pan where dirt, water, and sludge are
likely to collect. The strainer screen is held to the float
by a holding clip. The up and down movement of the
float is limited by stops.
The fixed strainer (fig. 6-23) is simply an inverted
funnel-like device, placed about 1/2 inch to 1 inch from
the bottom of the oil pan. This device prevents any
sludge or dirt that has accumulated from entering and
circulating through the system. The assembly is
attached solidly to the oil pump in a fixed position.
The oil filter removes most of the impurities that
have been picked up by the oil, as it circulates through
the engine. Designed to be replaced readily, the filter is
mounted in an accessible location outside the engine.
There are two basic filter element configurationsthe
cartridge type and spin-on type.
Figure 6-23.Oil pickup and strainer.