Operation and maintenance manual

QSB4.5 and QSB6.7 Air Cleaner Restriction
Section 4 - Maintenance Procedures at 250 Hours or 3 Months Page 4-1
Maintenance Procedures - Overview
General Information
All maintenance checks and inspections listed in previous
maintenance intervals must also be performed at this
time, in addition to those listed under this maintenance
interval.
Air Cleaner Restriction
Maintenance Check
Mechanical Indicator
CAUTION
Never operate the engine without an air cleaner.
Intake air must be filtered to prevent dirt and debris
from entering the engine and causing premature
wear.
NOTE: Do not remove the felt washer from the indicator.
The felt washer absorbs moisture.
A mechanical restriction indicator is available to indicate
excessive air restriction through a dry-type air cleaner.
This instrument can be mounted in the air cleaner outlet
or on the instrument panel. The red flag (1) in the window
gradually rises as the cartridge loads with dirt. After
changing or replacing the cartridge, reset the indicator by
pushing the reset button (2).
Restriction or vacuum indicators need to be installed as
close as possible to the turbocharger air inlet in order to
obtain a true indication of restrictions.
Vacuum Indicator
Vacuum switches actuate a warning light on the
instrument panel when the air restriction becomes
excessive.