Air filters on dusty sites: when to clean and when to replace

On sandy and dusty sites, the air filter works many times harder than in normal conditions. Dust that gets past a damaged filter enters the engine and acts like sandpaper on the pistons and rings. The result is oil consumption, power loss and an engine that needs an overhaul early.

There are two filters

• The outer (primary) filter: catches most of the dust, and is the one you inspect and replace regularly.
• The inner (safety) filter: backup protection if the outer one fails. Never clean it; replace it per the manual, or every second or third outer filter change.

When to replace the outer filter

• The restriction indicator shows red or reaches the mark.
• It has a tear, a hole, or a damaged rubber seal.
• It has been cleaned several times and no longer recovers.
• It is due in the service schedule.

If you clean it temporarily

1. Remove the filter gently without knocking it on the ground.
2. Blow air from the inside out at low pressure, never the other way.
3. Hold it up to a light: if light shines through a spot, there is a hole and it must be replaced.
4. Wipe the inside of the housing with a clean cloth before refitting.
5. Make sure the cover is sealed properly with no air leaking past the sides.

Summary

The air filter is one of the cheapest service parts, and the engine is one of the most expensive. On dusty sites, always keep a spare filter in the machine.