Chevrolet Sonic Repair Manual: Fuel System Cleaning

Note:

If the fuel filter is plugged, the fuel tank should be inspected internally and cleaned if necessary.

1. Drain the fuel tank. Refer to  Fuel Tank Draining.
2. Remove the fuel pump module assembly. Refer to  Fuel Tank Fuel Pump Module Replacement.
3. Inspect the fuel pump module strainer. Replace the pump module assembly if the fuel strainer is contaminated.

Note:

When flushing the fuel tank, handle the fuel and water mixture as a hazardous material. Handle the fuel and water in accordance with all applicable local, state, and federal laws and regulations.

4. Flush the fuel tank with hot water.
5. Pour the water out of the fuel sender assembly opening in the fuel tank. Rock the fuel tank in order to be sure that the removal of the water from the fuel tank is complete.
6. Allow the tank to dry completely before reassembly.
7. Disconnect the fuel feed pipe at the engine fuel rail. Refer to  Plastic Collar Quick Connect Fitting Service.

Note:

Only use oil-free compressed air to blow out the fuel pipes.

8. Clean the fuel pipes by applying air pressure in the opposite direction of the fuel flow.
9. Connect the fuel feed pipe to the engine fuel rail. Refer to  Plastic Collar Quick Connect Fitting Service.
10. Install the fuel pump module assembly. Refer to  Fuel Tank Fuel Pump Module Replacement.