Intake Restriction - Navistar International DT 466 Diagnostic/Troubleshooting Manual

7. Intake Restriction

Figure 297
Purpose
To check for restriction in the air intake system likely
to cause engine performance problems.
NOTE: High intake or exhaust restriction can cause a
large amount of black smoke.
Tools
• Gauge Bar (magnehelic)
• Test line
Procedure
WARNING: To avoid serious personal injury,
possible death or damage to the engine or
vehicle, read all safety instructions in the "Safety
Information" section of this manual.
1. Inspect the following parts for restriction, damage
or incorrect installation:
• Air filter inlet and ducting (includes hood)
• Air inlet hoses and clamps
• Air filter housing, filter element, and gaskets
• Chassis mounted CAC and piping
• Air filter restriction indicator or gauge
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
6 PERFORMANCE DIAGNOSTICS
Figure 298 Low restriction
Figure 299 High restriction
NOTE: Intake restriction should be below 25 in H
When the filter element reaches maximum allowable
restriction, the yellow indicator will reach the top of
window and automatically lock in this position.
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
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