DESC R IPT IO N
nections for a restriction indicator to indicate a dirty
The engine air intake system consists of an air
air cleaner. The air cleaner is the dry-type with a
cleaner and associated piping for channeling the air
from the atmosphere to the engine intake manifold.
The intake pipe also provides the necessary con-
M A IN T EN AN C E
Check for Filter Restriction.
As a dry cleaner element becomes loaded with dust,
Dust passing the air cleaner, ev en through small
the v acuum on the engine side of the air cleaner (at
holes, can cause rapid engine wear. Ensure all
the air cleaner outlet) increases. The v acuum is
connections between the air cleaner and the engine
generally measured as restriction in inches of water.
are tight and sealed. If these connections are all
well sealed, and there is still evidence of dust
The engine manufacturer places a recommended
leakage, check the following places for possible
limit on the amount of restriction the engine will
stand without loss in performance before the ele-
ment must be cleaned or replaced. DDA allows 25.0
inches (63.5 cm) of water maximum at maximum
Dust that gets by the air cleaner system
gov erned rpm with a dirty air cleaner. Cummins
can often be detected by looking for
allows 20 inches (50.8 cm) of water maximum with a
dust streaks on the air transfer tubing
dirty air cleaner at maximum gov erned rpm. CAT
or just inside the intake manifold inlet.
allows 30 inches (76.2 cm) of water maximum at
maximum gov erned rpm with a dirty air cleaner.
Inspect the air cleaner outlet tube for damage.
Mechanical gauges, warning dev ices, indicators, and
Ensure the element gasket washer is not
the air cleaner restriction reaches this recommended
damaged and the washer's rubber face seals
limit. These gauges and devices are generally
against the element.
reliable, but the water manometer is the most
accurate and dependable.
Inspect the element gasket for damage.
To use the manometer, hold it v ertically and fill both
Check for structural failures. Any damaged
legs approximately half full with water. One of the
parts must be replaced.
upper ends is connected to the restriction tap
Inspect the restriction indicator tap for leaks.