What is the purpose of a crankcase breather?

The purpose of a crankcase breather is to prevent pressure from building up inside the crankcase. As an engine operates, it generates various gases and vapors, including combustion gases that can seep into the crankcase from the combustion chamber. These gases can increase the internal pressure, which can lead to oil leaks, seal failures, and potentially damage engine components.

The crankcase breather allows these gases to escape, maintaining a consistent internal pressure within the crankcase. This not only protects the integrity of the engine's seals and prevents oil leaks, but it also ensures optimal operation of the engine by allowing the crankcase to maintain a balanced environment. Keeping the crankcase at the proper pressure is vital for engine performance and longevity, as it supports the effective lubrication of all moving parts and reduces the risk of buildup that could otherwise hinder engine efficiency.