VALVE (EXHAUST) 6H3187 - Caterpillar

A service indicator may be mounted on the air cleaner element or in a remote location.
Illustration 1 g00760342
Service indicator
Some engines may be equipped with a different service indicator.Observe the service indicator. Clean the air cleaner element or replace the element when any of the following conditions occur:
The yellow diaphragm enters the red zone.
The red piston locks in the visible position.
The air restriction reaches 3.75 kPa (15 inch of H2O).
Illustration 2 g00760341
Service indicator on an air cleaner for crankcase ventilation
Some engines are equipped with an air cleaner for the crankcase ventilation intake air. The air cleaner is mounted on a camshaft cover. Clean the air cleaner element or replace the element when any of the following conditions occur:
The yellow diaphragm enters the red zone.
The red piston locks in the visible position.
The air restriction reaches 0.25 kPa (1 inch of H2O).
The air cleaner is saturated with oil.Inspect the service indicator daily for cracks, holes, or loose fittings. If any of these conditions are present, replace the service indicator.Test the Service Indicator
Service indicators are important instruments.
Apply vacuum (suction) to the service indicator.
Reset the service indicator.If the yellow core does not latch at the greatest vacuum, or if service indicator does not reset easily, obtain a new service indicator. If the new service indicator will not reset, the fitting for the service indicator may be plugged.
Illustration 3 g00351792
Porous filter
A porous filter is part of the fitting that is used for mounting of the service indicator. Inspect the filter for cleanliness. Clean the filter, if necessary. Use compressed air or a clean, nonflammable solvent.Note: When service indicator is installed, excessive tightening may crack the top of the service indicator. Tighten the service indicator to a torque of 2 N m (18 lb in).Replace the service indicator annually regardless of the operating conditions.