Paccar MX-11, Operator'S Manual, Page: 96 / 121

on the air filter housing (an in-cab
restriction gauge is optional in some
models). Service the filter elements when
the air inlet restriction indicator indicates
that service is needed. Paper elements
require care and proper handling because
they are critical to engine service life.
The engine air filter is located on the top of
the engine just below the hood. There are
four fasteners that hold the cover to the
filter housing.
If the vehicle has the under hood air intake
option, the air intake solenoid and the
airline may need to be removed to access
the air filter.
NOTE
Be sure to check your vehicle for an
ember pack or pre-cleaner filter when
servicing the engine air filter.
Perform the following maintenance
procedures according to the Preventative
Maintenance Schedule.
Check and correct for restriction:
• Service air filter element when air
inlet restriction gauge indicates
service is needed
• Check hose/pipe condition –
deterioration/signs of leaking
• Check hose clamp torque
Replace Engine Air Filter
If the vehicle is equipped with Cab
mounted air cleaner and under hood air
intake option, remove the air solenoid first..
1. Park the vehicle. Set the parking
brake and turn the ignition OFF.
2. If the air cleaner is under the hood,
open the hood to access the air
filter housing.
3. Loosen the hardware that holds the
housing cap to the main filter
enclosure.
4. Pull the air filter housing cap away
from the main enclosure to access
the filter.
5. Visually inspect the filter housing,
enclosure, and hardware for
damage.
6. The filter can be removed by
gently pulling it directly out of the
main enclosure. Be careful not to
drop or tap the filter on the housing
during removal as this could loosen
dirt and dust trapped in the filter.
DO NOT clean or reuse the original
filter.
7. Inspect the sealing surfaces and
clean out any debris from the
inside of the filter enclosure before
installing the new filter. Be careful
to not push any contaminant into
the engine inlet.
8. Visually inspect the new filter prior
to installation. There should not be
any damage to the filter media or
gaskets, such as dents, dings,
cracks, or holes.
9. After installing the filter, inspect for
a good seal, if possible.
10. Install the filter housing cap and
tighten the hardware. DO NOT use
the housing cap to drive the filter
into position.
11. Start the engine and allow the air
system to reach operating
pressure. Activate the under hood
air switch and verify that there are
no air leaks.
Air Filter Restriction Indicator
(Option)
An Air Filter Restriction Indicator may be
installed on the air filter housing or air
induction piping for access to clean, filtered
air.
ENGINE MAINTENANCE - Maintenance Procedures
94 Y53-1166-1M1 (10/2020)
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