TRUCK SERVICE MANUAL
Fig. 7 Typical Oil Bath Air Cleaner
Combination Oil Bath and Dry Type Air Cleaner
The combination oil bath and dry type air cleaner is a
two-stage air cleaner. Air entering the air cleaner first flows
through an oil bath type air cleaner and then through a dry
type element before entering the engine. Fig. 8 illustrates a
typical combination oil bath and dry type air cleaner with an
Fig. 8 Typical Combination Oil Bath And Dry Type Air Cleaner
Air Cleaner Restriction Indicators
Air cleaner restriction indicators used in conjunction with
dry type air cleaners perform the function which their name
implies. Actuated directly by a pressure drop between air
cleaner and engine, restriction indicators show when an air
cleaner element has reached maximum allowable restriction.
The restriction indicator shown in Fig. 9 contains a red
signal band located in the indicator housing above the window
and is not visible when engine is stopped if air cleaner does
not require servicing.
Fig. 9 Air Cleaner Restriction Indicator
After starting the engine, the band may drop sufficiently
to be seen in upper part of window. This must not be
mistaken as a signal for element service.
During operation, the red signal band will gradually drop
in window as dirt accumulates in filter element. When filter
element reaches the maximum allowable restriction, the red
band reaches the bottom of window and automatically locks in
this position. The band will remain fully exposed even after
stopping the engine. When this happens, filter element
service is required.
CTS-2056N Page 4
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