HARNESS AS-LIGHTING 4416376 - Caterpillar

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. Note: There are two types of open circuit crankcase breather that may be installed on the engine, a filtered breather and an unfiltered breather.
Illustration 1 g03531035
Typical unfiltered breather
Illustration 2 g03531037
Typical filtered breather
If there is excessive crankcase pressure, check the breather for blockages, and debris. Refer to Disassembly and Assembly Manual for the correct procedure. Inspect the inside of the valve mechanism cover for debris. Ensure that all of the debris is removed. Note: The breather (1) that is within the valve mechanism cover (2) is not a serviceable item. The breather should only be renewed if the breather is damaged.
Remove the breather tube (3) from the breather (1) and check for obstructions. If the breather tube is obstructed, use low-pressure air to remove the obstruction. If a filtered breather assembly is installed, check that the filter element is free from oil. Ensure that the filter has been renewed at the correct service interval. Refer to the Operation and Maintenance Manual for the correct procedure. If a blockage is inside the cover (2), remove the cover. Refer to Disassembly and Assembly, "Crankcase Breather - Remove and Install" for the correct procedure. Check the breather for cracks or external damage. If the breather is faulty, renew the breather. Note: The new filter must not be filled with oil when the canister is renewed.