How to maintain and care for the engine air filter to ensure it remains efficient and durable?

Air compressor consumables comprise three types: air filters, oil filters, and oil-air separators. Air filters are further categorized into dry-type and wet-type variants based on whether the filter element is oil-impregnated. Regardless of material composition, proper maintenance of the engine air filter during operation enhances its performance and minimises consumable wear. Below we outline the maintenance procedures for both types of air filter.

I. The wet-type air filtration assembly comprises a dust extraction hood, baffle plates, dust discharge port, and dust collection cup. Therefore, when maintaining and servicing the engine air filter, note the following:

1. Regularly inspect and clear the dust discharge holes on the centrifugal dust extraction hood to ensure unobstructed flow. Remove dust adhering to the baffle plates and empty the dust collected in the dust collection cup (ensuring the dust volume within the container does not exceed one-third of its capacity). When installing the air cleaner, ensure the rubber gasket at the connection point is properly sealed to prevent air leakage. Failure to do so may cause airflow short-circuiting, reducing rotational air velocity and significantly diminishing dust removal efficiency.

2. During maintenance of the engine air cleaner, also observe whether the shape of the dust hood or deflector plate has changed. Should any deformation occur due to impact, promptly restore them to their correct shape to prevent altered airflow patterns from diminishing filtration efficiency.

3. Refrain from adding oil to the dust collection cup (or dust collector tray), as oil may splatter onto the filter assembly’s dust discharge port or baffle plates. This causes dust particles to adhere to these components, thereby reducing the filter’s separation capacity.

I. The wet-type air filtration assembly comprises a dust extraction hood, baffle plates, dust discharge port, and dust collection cup. Therefore, when maintaining and servicing the engine air filter, note the following:

1. Regularly inspect and clear the dust discharge holes on the centrifugal dust extraction hood to ensure unobstructed flow. Remove dust adhering to the baffle plates and empty the dust collected in the dust collection cup (ensuring the dust volume within the container does not exceed one-third of its capacity). When installing the air cleaner, ensure the rubber gasket at the connection point is properly sealed to prevent air leakage. Failure to do so may cause airflow short-circuiting, reducing rotational air velocity and significantly diminishing dust removal efficiency.

2. During maintenance of the engine air cleaner, also observe whether the shape of the dust hood or deflector plate has changed. Should any deformation occur due to impact, promptly restore them to their correct shape to prevent altered airflow patterns from diminishing filtration efficiency.

3. Refrain from adding oil to the dust collection cup (or dust collector tray), as oil may splatter onto the filter assembly’s dust discharge port or baffle plates. This causes dust particles to adhere to these components, thereby reducing the filter’s separation capacity.

II. Dry-type air filter assemblies comprise paper filter elements and sealing gaskets. When maintaining and servicing engine air filters, observe the following:

1. Regular inspection and proper cleaning

· Inspection interval: Recommended every 5,000 to 8,000 kilometres or every six months. Shorten intervals for frequent operation in dusty environments (e.g., construction sites, rural dirt roads).

· Cleaning method:

· After removing the filter element, gently brush away large surface particles with a soft-bristled brush following the pleat direction.

· Then lightly tap the end face of the filter element on a flat surface to dislodge deeper-seated dust.

· The most critical step: Securely plug both ends of the filter element with a clean cotton cloth or rubber stopper. Then, using compressed air or a bicycle pump, blow air from the inside outwards through the element. Crucially, ensure the air pressure does not exceed 0.2-0.3MPa (roughly equivalent to the force exerted when vigorously pumping a standard bicycle tyre), to prevent high-pressure air from damaging the filter paper.

2. Strictly prohibit liquid cleaning

· Never use water, diesel, or petrol to clean, maintain, or service the engine air filter. Because:

· Water causes the filter paper to become damp and warped. Diesel and petrol clog the microscopic pores of the filter paper, obstructing airflow and increasing engine intake resistance. This leads to higher fuel consumption and reduced power output.

· More dangerously, residual diesel vapour after cleaning may be drawn into the cylinder, potentially causing engine runaway (acceleration out of control) and severe engine damage.

3. When servicing and maintaining the engine air filter, promptly replace any damaged components.

Replace with new parts immediately and discontinue use if any of the following conditions arise:

· Filter element rupture: Even a small hole allows unfiltered air into the engine.

· Filter element deformation: Warped or uneven upper/lower surfaces compromise sealing integrity.

· Aged sealing rings: Rubber seals lose their sealing function once they become aged, deformed, or damaged.

4. During maintenance of the engine air filter, ensure proper installation to prevent leaks

· Sealing first: When installing, always verify that all gaskets and sealing rings at connection points are correctly positioned and fitted. Omissions or incorrect installation may cause air to bypass the filter element (known as ‘air bypassing’) and enter the engine directly with dust.

· Moderate Tightening: Do not overtighten the wing nuts securing the filter housing. Hand-tighten until resistance is felt, then apply a slight additional turn. Excessive tightening may crush or deform the housing.

Additional note:

5. A handy tip for determining when to replace the air filter

In dim lighting, remove the cleaned filter element and place a lit torch or mobile phone light inside it. Observe from the outside. If light shines through evenly across most areas, the filter is still relatively clean and can be reused. If light transmission is poor across most areas, indicating severe pore blockage, replacement is necessary.