BIT-END 8E4542 - Caterpillar

A general visual inspection should be made to the air inlet and exhaust system. Make sure that there are no signs of leaks in the system.There will be a reduction in the performance of the engine if there is a restriction in the air inlet system or the exhaust system.
Hot engine components can cause injury from burns. Before performing maintenance on the engine, allow the engine and the components to cool.
Making contact with a running engine can cause burns from hot parts and can cause injury from rotating parts.When working on an engine that is running, avoid contact with hot parts and rotating parts.
Inspect the engine air cleaner inlet and ducting in order to ensure that the passageway is not blocked or collapsed.
Inspect the engine air cleaner element. Replace a dirty engine air cleaner element with a clean engine air cleaner element.
Check for dirt tracks on the clean side of the engine air cleaner element. If dirt tracks are observed, contaminants are flowing past the engine air cleaner element and/or the seal for the engine air cleaner element.
For engines with plastic valve mechanism covers, if you experience excessive crankcase pressure, remove the valve mechanism cover and check the end of the shroud for a skin of plastic. If the end of the shroud has a skin of plastic, remove the skin of plastic. Ensure that all of the debris is removed.
If the breather tube is made of plastic, use low pressure air to check for a blockage in the breather tube. If a blockage is inside of the connector, the cover assembly must be replaced. A broken valve mechanism cover will result if you try to remove the connection.