Crankcase Filter: Description and Operation

All internal combustion engines produce small amounts of blow-by gasses. These are gasses that by-pass the piston rings and pass into the crankcase. These blow-by gasses are the result of the high pressure developed within the combustion chambers during the combustion process. They contain undesirable pollutants. To prevent blow-by gasses from entering the atmosphere, the PCV system is used. The crankcase ventilation system vents the blow-by gasses into the intake system to be burned, and allows for proper crankcase ventilation.

Crankcase Housing Breather Hoses:

The system incorporates a crankcase breather and screen #3 located on the engine block. The breather vent hose #1 is attached between the crankcase breather and the air intake. A calibrated vacuum orifice is connected between the breather hose and the vacuum hose. The restrictor orifice #4 allows vacuum hose #2 to vent blow-by gasses into the intake manifold. This helps control crankcase pressure.