Air Cleaner Restriction Indicator - Navistar MaxxForce 7 Operation And Maintenance Manual

SECTION 3 – INSTRUMENTS, INDICATORS, AND SWITCHES

Air Cleaner Restriction Indicator

Air restriction is resistance of airflow through the air cleaner.
Accurate air restriction is measured at maximum airflow.
Figure 24 Air Cleaner Restriction Indicator
Air cleaner restriction is measured by an air restriction indicator.
The restriction indicator may be located anywhere within the air
induction system or instrument panel depending on your specific
application.
Air Restriction Indicator Calibration
• The indicator is calibrated in inches of water.
• The indicator should be tested periodically (using a master
vacuum gauge) to ensure a correct calibration.
Air Restriction Indicator Operation
• The yellow position indicator progressively fills the window
as air filter restriction increases, locking at the highest
restriction at full load.
• When the yellow position indicator reaches and locks in the
red zone, a new air filter should be installed at the earliest
convenience.
NOTE: If the yellow indicator locks in the red zone, it is not
necessary to shut down the engine immediately, but a new air
filter should be installed at the earliest convenience.
Air Restriction Indicator Reset
• Once the filter has been changed reset the air restriction
indicator as follows:
• If the air restriction indicator is mounted on the air
cleaner, push the button on the indicator to reset.
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