COVER 1124757 - Caterpillar

will be a reduction in the performance of the engine if there is a restriction in the air inlet system or the exhaust system.The air flow through the air silencer may have a restriction. A restriction can be caused by a used filter element or a plugged filter element. The restriction must not be more than 4.0 kPa (15 inches of H2O). Air flow through the air silencer must not have a restriction of more than 1.25 kPa (5 inches of H2O) with a new filter element.Note: The restriction at the air silencer is the difference in the pressure between the atmospheric air and the air that has gone through the air silencer.Back pressure from the exhaust must not be more than 2.5 kPa (10 inches of H2O).Note: Back pressure is the difference in the pressure between the exhaust at the outlet elbow and the atmospheric air.