What is the primary function of the breathers in an engine?

The primary function of breathers in an engine is to maintain crankcase vacuum. Breathable systems are designed to allow gases and vapors generated during the combustion process to escape from the crankcase while preventing excess pressure build-up. Maintaining the correct crankcase pressure is crucial since it helps ensure proper lubrication by allowing oil to circulate correctly throughout the engine components.

Additionally, a proper vacuum in the crankcase prevents oil leaks and minimizes contaminants from entering the engine's internal components. While filtering air entering the engine or supplying fuel are important functions in their own right, they relate more to other engine systems. Regulating engine temperature is handled by the cooling system, which involves radiators and coolant, rather than the breathers. Hence, maintaining crankcase vacuum is the correct answer as it highlights the essential role breathers play in the efficiency and longevity of an engine.