What Is The Air Filter Breather And Why Do You Need One?

An air filter breather, also known as a crankcase breather, is a critical component of an internal combustion engine‘s ventilation system. Its primary purpose is to manage the pressure and flow of gases within the engine’s crankcase, ensuring optimal engine performance and longevity.

Understanding Crankcase Ventilation

The crankcase, located at the bottom of the engine block, houses the crankshaft and other moving parts. As these parts reciprocate, they create blow-by gases, a mixture of air, fuel, and combustion byproducts that escape past the piston rings into the crankcase. Uncontrolled blow-by gases can lead to several problems, including:

• Increased crankcase pressure, which can cause oil leaks and damage to engine seals
• Formation of sludge and deposits in the crankcase and oil passages
• Reduced engine power and efficiency due to the presence of blow-by gases in the combustion chamber

The Role of Air Filter Breather

An air filter breather provides a controlled path for blow-by gases to escape the crankcase while preventing the entry of dirt and other contaminants. It typically consists of the following components:

• Filter element: A porous material that traps dirt and other particles from the incoming air
• Housing: A container that encloses the filter element and provides a connection point to the crankcase
• Vent tube: A hose that connects the breather to the engine’s intake manifold or air filter

Operation of Air Filter Breather

During engine operation, blow-by gases are forced from the crankcase through the vent tube into the air filter breather. The filter element traps any dirt or contaminants from the gases, allowing only clean air to pass through. The cleaned gases are then directed into the intake manifold or air filter, where they are mixed with the incoming air-fuel mixture and burned in the combustion chamber.

Types of Air Filter Breathers

Air filter breathers come in various types, including:

• Positive crankcase ventilation (PCV) breathers: These breathers use a vacuum from the intake manifold to draw blow-by gases out of the crankcase. They are commonly found in modern vehicles.
• Negative crankcase ventilation (NCV) breathers: These breathers use a vacuum from the exhaust system to draw blow-by gases out of the crankcase. They are typically found in older vehicles.
• Oil separator breathers: These breathers use a centrifugal force to separate oil droplets from the blow-by gases. They are often used in high-performance engines.

Benefits of Air Filter Breather

An air filter breather provides several benefits for an internal combustion engine, including:

• Reduced crankcase pressure: By providing a controlled path for blow-by gases to escape, an air filter breather helps maintain optimal crankcase pressure, preventing oil leaks and damage to seals.
• Improved engine performance: By preventing the accumulation of blow-by gases in the combustion chamber, an air filter breather helps improve engine power and efficiency.
• Reduced emissions: By trapping oil droplets and other contaminants from the blow-by gases, an air filter breather helps reduce engine emissions.

Maintenance and Replacement

Air filter breathers require regular maintenance and replacement to ensure optimal performance. The following guidelines should be followed:

• Inspection: Regularly inspect the air filter breather for any signs of damage or contamination.
• Cleaning: Clean the air filter breather housing and vent tube as needed to remove any accumulated dirt or debris.
• Replacement: Replace the air filter element according to the manufacturer’s recommendations or when it becomes visibly dirty or clogged.

Takeaways: The Importance of Air Filter Breathers

Air filter breathers play a vital role in the health and longevity of an internal combustion engine. By managing crankcase pressure and flow, they help reduce emissions, improve engine performance, and prevent costly repairs. Regular maintenance and replacement of air filter breathers are essential for maintaining optimal engine operation.

Frequently Asked Questions

Q: What are the symptoms of a clogged air filter breather?
A: Symptoms of a clogged air filter breather may include increased crankcase pressure, oil leaks, reduced engine power, and increased emissions.

Q: Can I clean an air filter breather myself?
A: Yes, you can clean an air filter breather housing and vent tube yourself using a suitable solvent. However, it is recommended to replace the air filter element according to the manufacturer’s guidelines.

Q: How often should I replace the air filter breather?
A: The replacement interval for an air filter breather varies depending on the vehicle and driving conditions. Typically, it should be replaced every 12,000-15,000 miles.