C 3500 Truck 2WD V8-6.6L DSL Turbo VIN 1 (2002)
Fuel Return Line: Testing and Inspection
From the Engine to the Tank
1. Disconnect the return line at the engine, metal collar.
2. Remove the fuel filler cap.
3. Apply 1 psi air at the fuel return line that leads back to the tank.
4. Listen at filler tube for air.
5. If air is present, return line is okay.
If air is not present, disconnect the return line at the sender assembly.
6. Retest using 1 psi at the fuel return line back to the tank.
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If air is present, the return line is okay. Check and replace the sender assembly.
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If air is not present, repair the restriction in the return line.
