GEAR-PLANETARY 1598169 - Caterpillar

Some engines may be equipped with a different service indicator.Some engines are equipped with a differential gauge for inlet air pressure. The differential gauge for inlet air pressure displays the difference in the pressure that is measured before and after the air cleaner element. As the air cleaner element becomes dirty, the pressure differential rises. If your engine is equipped with a different type of service indicator, follow the OEM recommendations in order to service the air cleaner service indicator.The service indicator may be mounted on the clean side of the air cleaner housing or in a remote location.
Illustration 1 g00103777
Typical service indicator
Observe the service indicator. The air cleaner element should be cleaned or the air cleaner element should be replaced when one of the following conditions occur:
The yellow diaphragm enters the red zone.
The red piston locks in the visible position.Test the Service Indicator
Service indicators are important instruments.
Check for ease of resetting. The service indicator should reset in less than three pushes.
Check the movement of the service indicator core when the engine is run at full load speed. The core should latch approximately at the greatest vacuum that is attained.If the service indicator does not reset easily, or if the core does not latch at the greatest vacuum, the service indicator should be replaced. If the new service indicator will not reset, the hole for the service indicator may be plugged.If necessary, replace the service indicator more frequently in environments that are severely dusty. Replace the service indicator annually regardless of the operating conditions. Replace the service indicator when the engine is overhauled, and whenever major engine components are replaced.Note: When a new service indicator is installed, excessive force may crack the top of the service indicator. Tighten the service indicator to a torque of 2 N m (18 lb in).