Air Cleaner Element Inspecting and Replacing
Important: Due to the variety of possible driving conditions (dirt roads, paved roads, etc.), it is critical to check the air restriction indicator, if so equipped. If the vehicle is not equipped with an air restriction indicator, inspect all components of the air intake system and air filter every six months. Replace the air filter every 12 months, or when filter restriction reaches 25 inH2O for diesel engines, or when the air restriction indicator is completely red for propane engines (if equipped with an air restriction indicator). More frequent inspections and/or filter replacement may be needed if the vehicle is being operated in a dusty environment, to avoid damaging the vehicle.
Inspecting
Remove and visually inspect the air filter for holes, tears, cracks, or other damage at the recommended interval. Remove loose debris, such as leaves or pine needles, from the filter housing. If the air filter is damaged, replace it. See of the S2 Chassis Workshop Manual for removal and installation instructions, or take the vehicle to an authorized Freightliner dealer.
Engine damage can occur if the air intake system is not properly maintained. Use the air intake restriction indicator to check for air intake system damage or leaks. See Fig. and see Fig.. Make sure the engine is off and note the existing reading on the indicator. Reset the indicator by pushing it down. See Fig. and see Fig.. Start the engine and take a short test drive. Check the indicator again and note the level of restriction on the indicator. A decrease from the previous level of restriction or a very low air restriction indicator reading (0 to 4 inH2O) could indicate an air intake system problem such as a damaged air filter, loose or disconnected air intake piping, or a disconnected or damaged air restriction indicator.
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Partial Restriction
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Full Restriction
Fig. 1, Air Restriction Indicator, Diesel Engines
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Partial Restriction
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Full Restriction
Fig. 2, Air Restriction Indicator, Propane Engines
Replacing
Notice: Do not use aftermarket air-cleaner elements. Aftermarket air-cleaner elements may not seal the housing correctly, which can lead to engine damage and potentially the loss of warranty. When replacing an air-cleaner element, use only the part listed in PartsPro for the serial number of the vehicle.
Replace the air filter every 12 months, or when filter restriction reaches 25 inH2O for diesel engines, or when the air restriction indicator is completely red for propane engines (if equipped with an air restriction indicator). See of the S2 Chassis Workshop Manual for removal and installation instructions, or take the vehicle to an authorized Freightliner dealer.