freightliner Custom Classic MT45 2022, Maintenance Manual

Page: 32 / 138

NOTICE
Do not clean or reuse the air filter. Cleaning and
reusing the the air filter increases the chances of
dirt entering the engine. Always replace with a
new air filter.
Replace the air filter every 12 months, or when filter
restriction reaches 25 inH
2
O for Cummins diesel
engines, or when the air restriction indicator is
completely red for gasoline and Detroit diesel
engines (if equipped with an air restriction indi-
cator). See Group 09 of the Walk-In Van Work-
shop Manual for removal and installation in-
structions, or take the vehicle to an authorized
Freightliner dealer.
09–02 Air Cleaner Filter Minder
Gauge Checking
The filter minder gauge measures the amount of air
restriction (in inches or millimeters of water vacuum)
in the air intake system. It is connected to the air in-
take tube by a vacuum hose and a small vacuum
filter. The gauge takes its measurements when the
engine is running at full load, and then locks in place
until reset. See
Fig. 1 or Fig. 2 as applicable to the
vehicle, for depictions of how the indicator appears
when the air intake is partially restricted and when it
is fully restricted and should be replaced.
09–03 Air Intake System
Inspecting
Check the air intake system for damaged or cracked
hoses, and for loose clamps. Also check the air filter.
2
H O VACUUM
2
H O VACUUM
25
20
15
10
7
PUSH TO RESET
IN
2
H O VACUUM
2
H O VACUUM
25
20
15
10
7
PUSH TO RESET
IN
A B
f090165 08/21/96
A. Partial Restriction B. Full Restriction
Fig. 1, Air Restriction Indicator, Cummins Diesel Engines
f090495 12/02/2011
A B
A. Partial Restriction B. Full Restriction
Fig. 2, Air Restriction Indicator, Gasoline and Detroit
Diesel Engines
Air Intake
09
Walk-In Van Chassis Maintenance Manual, June 2021
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