How to Change the Fuel Pump in a 2003 Mercedes E320

Removing the Old Fuel Pump
1. Pull your Mercedes onto car ramps and place the vehicle in park. Be sure to lock the emergency brake as well to prevent the possibility of rolling or sliding.
2. Pop the hood and remove the negative terminal from the battery, using a crescent wrench. This will stop the flow of power between the battery and the fuel pump.
3. Climb under the vehicle and locate the fuel pump just in front of the gas tank along the fuel line. The fuel pump will be slightly larger than the fuel line and will be accompanied by bolt ends on both sides, with an electrical lead coming off it.
4. Close the valve behind the fuel pump on the fuel line by twisting it clockwise until it is tight. This will stop the flow of fuel to the pump.
5. Remove the electrical connection on the pump, using a 12 mm socket wrench.
6. Remove the two bolt ends on both sides of the pump, using a crescent wrench, then slide the pump away from the line.
Installing the New Pump
7. Slide a new fuel pump into place on the line and replace the two bolt ends, once again using a crescent wrench.
8. Replace the electrical connection on the pump.
9. Reopen the valve behind the fuel pump by twisting it counterclockwise.
10. Climb out from underneath the vehicle and replace the negative terminal on the vehicle's battery.