All Timberjack skidders are equipped with a Donaldson dry type air cleaner. Some units consist of a single element, while others have a large element and a smaller safety element inside. On the single element units angled vanes on the outside of the element produce a swirling movement on the air. This causes large particles of contaminant to  settle out on the air cleaner walls where it is removed through the pulsating ejector at the bottom of the air cleaner housing.

The air is then drawn through the large pleated filter. If an inner safety filter is installed the air then passes through this filter and
on to the engine through the intake hose. To ensure that only clean air is entering the engine, the filter elements must be properly sealed at both ends, ie. the rubber gaskets must be clean and in good condition.
The wing nuts which hold the element in place must be tight. Also all connections in the air intake down stream from the air cleaner must be well sealed, and there must be no holes in the hose or tubing.