Express 3500 V8-6.6L DSL Turbo (2008)
Collar Quick Connect Fitting Service.
6. Cap off the fuel supply pipe on the engine with a rubber plug and a clamp.
Important: The fuel prime pump must be disabled before using the CH-48027 to diagnose the fuel system. Fuel pressure with the pump
running is more than the gage is designed to handle and may cause damage to the gage.
7. Remove the fuel pump relay. Crank the engine and observe the CH-48027 to see if the fuel injection pump is creating at least 10 inches Hg of
vacuum.
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If vacuum is present during cranking but bleeds off rapidly, repair the leak in the fuel supply line.
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If vacuum is not present during cranking, replace the fuel injection pump.
Important: Changes in engine speed can cause an increase of air bubbles that enter the EN-47969. An air pocket at the top of the
EN-47969 loop is considered a normal condition.
8. Remove the rubber plug from the fuel supply line and install the EN-47969. Create a vertical loop in the hose to observe the incoming fuel for air
bubbles. Command the Fuel Pump ON with a scan tool and prime the fuel system until all air has been purged. Start and run the engine for at least
10 minutes to allow the fuel system to stabilize. At a stabilized idle, observe the fuel entering the EN-47969 for air bubbles.
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If air bubbles were observed entering the transparent hose, test the fuel sender for leaks.
9. Install the fuel sender, fuel tank, and all fuel system connections and components that were previously disconnected. Leave the EN-47969
connected to the fuel supply line. Command the fuel pump ON with a scan tool and prime the fuel system until all air is purged. Start and run the
engine, while observing the fuel entering the transparent hose.
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If air bubbles are still present, refer to Diagnostic Aids.
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If no air bubbles are present, remove the EN-47969 and run the engine to ensure no fuel leaks exist.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. See: Computers and Control Systems/Testing and
Inspection/Diagnostic Trouble Code Tests and Associated Procedures/Verification Tests and Procedures
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Fuel Injection Pump Replacement
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Fuel Sender Assembly Replacement
