Navistar International DT 466 Diagnostic/Troubleshooting Manual page 231

Figure 292 Fuel supply line
1. Remove fuel supply line from suction side of fuel
pump and fuel filter housing.
Figure 293 Test fuel line
1. Clamp (2)
2. Clear plastic tube
3. Spare fuel line (half)
4. Sleeve seal (2)
2. Make a test fuel line.
• Use spare fuel line. (Make sure both sleeve
seals are good.) Cut a 3 inch section from
the center of the fuel line. Install clear plastic
line in place of removed section and secure
plastic line with clamps.
NOTE: The mechanic is expected to keep the fuel
test line for future diagnostics. Expense the fuel
test line as an essential tool and keep it with other
diagnostic tools. Warranty will not cover the cost
of the fuel test line.
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
6 PERFORMANCE DIAGNOSTICS
Figure 294 Test line installed
3. Install test fuel line.
4. Do one of the following:
5. Record results on Diagnostic Form.
6. Remove fuel test line and install original fuel line.
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
NOTE: Verify that sleeve seals are in good
condition.
• For Hard Start and No Start Diagnostics,
crank engine for 20 seconds and check for air
bubbles in the clear plastic line.
• For Performance Diagnostics, run engine at
high idle, no load and check for air bubbles in
the clear plastic line.
NOTE: Initially, fuel will be aerated due to draining
fuel from filter housing and strainer in previous
test.
• If fuel is aerated check for a leak in the suction
side of fuel system. See "Aerated Fuel" in
Section 4.
• If fuel is not aerated and fuel pressure is good,
continue with next test.
• If fuel is not aerated and fuel pressure is low,
do "Operation of Fuel Pump".
NOTE: Verify that sleeve seals are in good
condition.
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