LINK AS-TRACK 2389851 - Caterpillar

Never run the engine without an air cleaner element installed. Never run the engine with a damaged air cleaner element. Do not use air cleaner elements with damaged pleats, gaskets or seals. Dirt entering the engine causes premature wear and damage to engine components. Air cleaner elements help to prevent airborne debris from entering the air inlet.
Never service the air cleaner element with the engine running since this will allow dirt to enter the engine.
Remove the air cleaner cover and the element.
Cover the air inlet opening with a clean cloth, or seal with tape in order to prevent dirt and debris from entering the engine.
Clean the inside of the air cleaner cover and the body with a clean, dry cloth.
Wash the element in warm water and mild nonsudsing household detergent. Rinse the element after washing.
Inspect the element for deterioration. Replace the element if the element is deteriorated or torn.
Remove the seal from the air inlet opening. Install the element and the air cleaner cover.