Replacing The Fuel Filter In Your Ml320: Step-By-Step Guide

The fuel filter in a Mercedes ML320 is located under the vehicle, just in front of the rear driver-side tire. It is recommended that the fuel filter be replaced every 60,000 to 90,000 miles. To replace the fuel filter, first relieve the fuel system pressure and disconnect the negative battery cable. Remove the left rear wheel and plastic inner fender liner. Disconnect the fuel pipes from the fuel filter by compressing the locking catches and remove the breather hose from the filter assembly. Remove the filter securing clip and the filter/pressure regulator. Install a new fuel filter/pressure regulator and secure it with the clip. Reattach the breather hose and fuel lines to the filter assembly. Reinstall the plastic inner fender liner and left rear wheel, then reconnect the negative battery cable. Read the fault memory, encode the radio, and normalize the power windows. Start the vehicle and check for leaks.

Removing the rear wheel and fender liner

To remove the rear wheel and fender liner of your ML320, you will need to follow these steps:

• Park your car on a level surface and engage the parking brake. Loosen the lug nuts on the rear wheel with a lug wrench before jacking up the car. Place jack stands under the car for safety.
• Remove the rear wheel by fully unscrewing the lug nuts and lifting the wheel away from the car. Set it aside in a safe place.
• Locate the plastic inner fender liner, which is behind the rear wheel. It is held in place by several plastic clips and screws.
• Carefully remove the plastic clips and screws securing the fender liner in place. Some of the screws may be difficult to access, so you may need to use a screwdriver with an extension or a ratchet with a socket attachment.
• Once all the clips and screws are removed, carefully pull the fender liner away from the car. It may be necessary to wiggle it slightly to detach it from the vehicle.
• With the fender liner removed, you will now have access to the fuel filter, which is located just in front of the rear driver-side tire.

Remember to work safely and wear appropriate protective gear when performing any car maintenance or repairs.

Disconnecting the fuel lines

Before starting, make sure you have relieved the fuel system pressure and disconnected the negative battery cable.

Step 1: Remove the Fuel Lines

Using a pair of pliers, remove the clips holding the fuel lines in place on the top of the filter. Grip the nozzles of the fuel lines with the pliers and pull them straight out from the fuel filter nozzles. Be careful not to kink the fuel lines during this process.

Step 2: Remove the Fuel Filter Bracket

Loosen the nut securing the fuel filter bracket to the chassis using a wrench. Once the nut is loose, remove the bracket and set it aside.

Step 3: Remove the Old Fuel Filter

With the fuel lines and bracket disconnected, you can now remove the old fuel filter from its mounting bracket. Be gentle and take note of its orientation for installation of the new fuel filter.

Step 4: Prepare the New Fuel Filter

Before installing the new fuel filter, ensure that you have the correct part for your specific ML320 model. Some models require additional fuel lines to be installed with the new fuel filter. Refer to your owner's manual or consult a trusted mechanic if you are unsure.

Step 5: Install the New Fuel Filter

Insert the new fuel filter into the mounting bracket, ensuring that the arrow on the fuel filter points towards the front of the vehicle. Secure the fuel filter bracket onto the chassis with a wrench.

Step 6: Reconnect the Fuel Lines

Push the fuel lines back onto the fuel filter nozzles until you hear a “click” sound, indicating they are locked in place. Replace the clips over the fuel lines and ensure they are securely attached to the top of the fuel filter.

Step 7: Re-pressurize the Fuel System

Turn the key in the ignition to the “on” position but do not start the engine. This will prime the fuel lines and pressurize the fuel system.

Step 8: Check for Leaks

Before starting the engine, carefully inspect the fuel filter area for any signs of fuel leaks. Make sure all connections are secure and tight.

Now you can start the engine and take your ML320 for a test drive.

Remember to dispose of the old fuel filter properly and according to local regulations.

Removing the old fuel filter

To remove the old fuel filter from your ML320, you will need to relieve the fuel system pressure. Start by removing the negative battery cable. Next, relieve the pressure in the fuel tank by opening and then tightening the filler cap. It is important to ensure that the fuel lines are not kinked during this process.

Now, you can move on to removing the left rear wheel and the plastic inner fender liner. You will need to compress the locking catches to remove the fuel pipes from the fuel filter. The breather hose can then be removed from the filter assembly, followed by the filter securing clip.

Finally, you can remove the filter/pressure regulator from the housing. Be sure to note the orientation of the filter and any other components before removal, as this will aid in the installation of the new fuel filter.

Installing the new fuel filter

To install the new fuel filter, follow these steps:

• Install the new fuel filter into the mounting bracket, ensuring that the arrow on the fuel filter points towards the front of the vehicle.
• Secure the fuel filter bracket onto the chassis with a wrench.
• Push the fuel lines back onto the fuel filter nozzles until you hear a “click” sound.
• Replace the clips over the fuel lines and ensure they are securely attached to the top of the fuel filter.
• Turn the key in the ignition to the “on” position but do not start the engine. This will prime the fuel lines and pressurize the fuel system.
• Check for any fuel leaks around the fuel filter area.
• Start the engine and test drive the vehicle.

Reattaching the fuel lines

To reattach the fuel lines, you will need to follow these steps:

• Ensure that the arrow on the new fuel filter is pointing towards the front of the vehicle.
• Secure the fuel filter bracket onto the chassis with a wrench.
• Push the fuel lines back onto the fuel filter nozzles until you hear a “click” sound.
• Replace the clips over the fuel lines and ensure they are securely attached to the top of the fuel filter.
• Turn the key in the ignition to the “on” position but do not start the engine. This will prime the fuel lines and pressurize the fuel system.
• Check for any fuel leaks around the fuel filter area.
• Start the engine and test drive the vehicle.

It is important to note that you should always consult your owner's manual or a trusted mechanic for specific recommendations based on your vehicle's make, model, and year, as well as your driving habits and vehicle usage. Additionally, make sure to relieve the fuel system pressure and disconnect the negative battery cable before beginning any work on the fuel system.

Frequently asked questions