ELECTRICAL AR 3674420 - Caterpillar

Inlet Air Restriction (Air Cleaner Differential Pressure) - This gauge indicates the difference in air pressure between the inlet side and the engine side of the air filter element. The air cleaner differential pressure is measured at the air inlet of the turbocharger. As the air filter element becomes plugged, the difference in pressure between the two sides of the air cleaner element will increase. The nominal air filter differential pressure during normal engine operation is approximately 3 kPa (12 inches of H2O).To avoid the derating of engine operation, replace the air filter element before reaching the maximum differential pressure of 6.2 kPa (25 inches of H2O).For instructions on replacement of the air filter elements, see this Operation and Maintenance Manual, "Engine Air Cleaner Element - Replace" topic.