Maintenance Manual
09–01 Air Cleaner Inspection
Restriction of air flow through the air cleaner element
is measured at the tap in the air cleaner outlet.
Check the restriction indicator at the air cleaner or in
the cab if the vehicle is equipped with a dash-
mounted restriction gauge.
Vehicles may be equipped with either a manual-reset
restriction indicator with graduations (
Fig. 1), or a
go/no-go restriction indicator without graduations (
Fig. 2).
1. Inspect the air restriction indicator to see if air
restriction equals or exceeds the maximum al-
lowable restriction. For instructions, see Group
09 of the New Cascadia Workshop Manual.
NOTICE
Do not use aftermarket air-cleaner elements. After-
market air-cleaner elements may not seal the
housing correctly, which can lead to engine dam-
age and potentially the loss of warranty. When re-
placing an air-cleaner element, use only the part
listed in PartsPro for the serial number of the ve-
hicle.
2. If necessary, replace the air cleaner element. For
air cleaner element replacement instructions, see
Group 09 of the New Cascadia Workshop
Manual.
3. Inspect the air cleaner housing for cracks, leaks,
or any other damage. If the air cleaner housing
or element is damaged, replace it.
4. Inspect the forward and rear mounting isolators
for damage. See
Fig. 3. Ensure the bonds be-
tween the rubber and the steel plates are com-
pletely intact. See
Fig. 4.
If a mounting isolator is damaged, replace it. For
isolator replacement instructions, see Section
09.01 of the New Cascadia Workshop Manual.
5. Check that the quick connect fitting for the air
compressor supply line is fully engaged with the
air cleaner. See
Fig. 5.
6. Remove the pre-cleaners (if so equipped) from
the hood plenum, then clean them with com-
pressed air.
7. Reset the air restriction indicator.
8. Each time the air cleaner housing is replaced,
perform the procedures in
MOP 13–01.
08/07/2007 f090452
Fig. 1, Manual-Reset Air Restriction Indicator,
Graduated
04/08/2005 f090431
Fig. 2, Manual-Reset Air Restriction Indicator, Go/
No-Go
Air Intake 09
New Cascadia Maintenance Manual, January 2017 09/1