Engine Breather Filters

A vehicle's crankcase ventilation system includes the crankcase breather filter, often known as the crankcase vent filter (CCV). In the internal combustion engines of a relatively small number of vehicles, such as vintage/muscle cars, race cars, and motorcycles, this filter is a component of the crankcase ventilation system. However, it can also be found on other engines, such as diesel ones like the Dodge Cummins.
Gases are forced into the crankcase by the engine's pistons as it operates. These gases result in a buildup of pressure that depletes the engine's ability to operate. The crankcase system's goal is to better relieve this pressure by either releasing extra gas to the atmosphere or returning it to the engine.