BUSHING 3024181 - Caterpillar

Commercial EnginesThere has been little emphasis given to the maintenance of air filter indicators. Air filter indicators, such as the 8N2694 and 1W0613 Air Filter Indicators, are inexpensive but important instruments. Their function is to show air filter restriction as the filter is progressively filled (plugged) with dust. The indicator can help prevent unnecessary serving. The indicator can also help avoid running the engine with an excessively plugged air filter. They can help get the most life out of your air filter.
In average dust conditions, the air filter indicators should be tested for proper operation every 250 hours or when the air filter elements are serviced. If the dust is severe, the indicator operation should be checked every day. To check the operation of the air filter indicator do the following:
* Check for ease of resetting-should reset in less than a maximum of three pushes.* Check for movement of the yellow core when the engine is accelerated to high idle. The yellow core should latch at/or very close to the highest vacuum obtained.If the indicator will not reset easily or the indicator yellow core will not latch at the highest vacuum attained, the indicator should be replaced. If the indicator does not reset, the filter in the air filter restriction sensing hole may be plugged.
THE AIR FILTER INDICATOR SHOULD BE REPLACED DURING ENGINE OVERHAULS AND/OR MAJOR ENGINE COMPONENT REPLACEMENT. THE AIR FILTER INDICATOR SHOULD BE REPLACED ONCE PER YEAR.
When installing an air filter indicator, excessive tightening force may crack the top of the indicator. Tighten the indicator to a torque of 2 N m (18 lb in). A video tape, PEVN1736, "Caterpillar Air Filter Service Indicator" to further explain the use and testing of the air filter indicator.