Changing Fuel Filters In A Mini: Step-By-Step Guide

If you are experiencing starting, stalling or fuel economy problems with your Mini, you may have a dirty or clogged fuel filter. The fuel filter in a Mini is easy to get to and replace. You will need about an hour of your time and no special tools. Here is a step-by-step guide on how to change the fuel filter on a Mini 2005.

Step 1 – Remove the rear seat

There is an access port to the fuel filter under the rear passenger side seat. You will need to remove the passenger side rear seat in order to access the fuel filter port. The seat comes out in two parts. Remove the bolt in between the two seats and pull up on the locking mechanism to pull out the back of the seat. You'll need to swivel the seat to get the other side to come out. Once the back is off, lift the bottom seat from the front edge and it will pop right up and out.

Step 2 – Locate the fuel filter housing

Once the seats are out, you will see the access panel for the fuel filter housing on the floor on the passenger side. Before starting your work, lay some plastic drop cloth all around the housing to protect the fabric from absorbing any spilled fuel.

Step 3 – Remove the filter assembly from the housing

Use a 10mm socket and ratchet to remove the five nuts that hold the panel in place. Once the panel is off, vacuum or clean the area so you don't get any debris into the filter housing once you remove it. The top of the fuel filter housing is secured with a locking ring. Use a flat-head screwdriver to turn the ring counterclockwise. Once it is unlocked, get a rag under the fuel line and disconnect it by pressing in on the tabs. Be prepared for a little spray and protect yourself as well as the area with shop rags. Once the fuel line is disconnected, remove the lock ring and set it aside. Use a flat-head screwdriver to pry up the filter assembly a few inches, then grasp the top of the assembly and twist while pulling up to remove it completely.

Step 4 – Remove and replace the fuel filter and O-rings

Once the assembly is out, you can remove and replace the old filter and O-rings. The filter will pull right out. You will need to suck out the nasty fuel from the bottom of the housing in order to expose the lower O-ring. Remove the lower O-ring as well as the upper O-ring that is inside the cap. Apply some Vaseline to both the new upper and lower O-rings before installing them. Grab the internal assembly inside the housing after you install the lower O-ring and insert the new filter firmly into it. You will likely need to twist the filter back and forth to get it to solidify in place. Once the filter is in, you may need to pull up the assembly a little from the housing to get the cap back in place. When installing the cap, you will have to push down and twist in the opposite direction of removal to lock it in place. Drop the assembly back down into the housing.

Your replacement kit also comes with a larger gasket ring that goes around the top of the assembly. This can only go on in one direction, so make sure you are putting it on the correct way and make sure it is completely flush with the edge of the housing. Replace the locking ring, hand-tighten only and then give it a slight whack with a hammer or mallet to make sure it is snug. Be gentle because you do not want to strip it. Replace the housing cover and tighten the five 10mm nuts. Reattach your fuel line. Wipe up any spilled fuel on your drop cloth and then dispose of the drop cloth. Replace your seats.

Remove rear seat

To remove the rear seat of a Mini Cooper, follow these steps:

First, tilt and slide the front seats forward as far as they can go to make room in the back seat area.

The rear seat is removed in two parts. Start by lifting up on each side of the rear seat base to unclip the front of the seat base. Then, remove the anchor point covers by pulling them to unclip. Finally, remove the seat base.

For the upper part of the seat, fold the seat backs forward and press the release latch on the central pivot, which holds both seat backs. Lift the pivots out, one seat back at a time, and fold them back upward to 45 degrees, which will allow the outside pivot to slide free. Repeat this process for the other seat back.

The lower cushion is held in place by clips on the floor. Remove the plastic grommets for the child seat anchors. Reach under the front edge and pull up to release it. With the front loose and angled up, press down in the centre of the seat to pop the rear hook free. Pull up on the cushion to pop it free of the clips.

Disconnect negative battery lead

Disconnecting the negative battery terminal is a standard procedure when working on your car. It is also important to disconnect the battery when working on the fuel system. Here is a step-by-step guide on how to disconnect the negative battery terminal on a Mini:

Step 1: Put on Safety Gear

Before you begin, make sure to put on safety gear such as safety glasses and gloves. It is also recommended to remove any jewellery. These precautions will help protect you from electrical hazards and sparks.

Step 2: Locate the Battery

The battery is usually located under the hood of your Mini, but in some models, it may be in the trunk. Refer to your owner's manual to determine the exact location.

Step 3: Identify the Negative Terminal

The negative terminal is typically denoted by a "-" symbol and a black cable. It is important to correctly identify the negative terminal to avoid any mistakes during the disconnection process.

Step 4: Disconnect the Negative Terminal

Using a suitable wrench, loosen the nut on the negative terminal. Make sure that the black cable is moved away from the terminal to avoid any accidental contact. It is crucial to only disconnect the negative terminal first, as removing the positive terminal first can create a hazardous situation.

Step 5: Secure the Cable

After disconnecting the negative terminal, ensure that the cable is securely moved away from the battery and cannot accidentally come into contact with any metal parts or the battery itself. You may use a cloth or a plastic cup to cover the terminal as an extra precaution.

Step 6: Optional - Disconnect Positive Terminal

If you need to completely disconnect the battery, you may also disconnect the positive terminal. However, this step is not necessary for most procedures. Remember to always disconnect the negative terminal first and reconnect it last.

Remember to exercise caution when working with your vehicle's electrical system. If you are unsure or uncomfortable with any part of the process, it is recommended to consult a professional mechanic or a repair shop.

Remove access panel

To remove the access panel for the fuel filter, you will first need to remove the rear seat. There are two circular metal covers bolted to the floor of the car. The fuel filter is located under the access cover on the right (passenger's side) of the car. To access it, remove the 10mm nuts holding the cover in place and then carefully pry the cover up and off the floor.

• Remove the rear seat cushion: Pry out the four plastic covers at the rear edge of the seat. It will take a little force to remove them from the seat. Take care to pry them out at the outer edge of the cover. The inner part of the cover flips open and it is easy to damage this flap. Once all the covers are removed, pry up the front edge of the seat cushion. It should pop off with a little force.
• Remove the access panel: You will now see two circular metal covers bolted to the floor of the car. The fuel filter is located under the access cover on the right (passenger's side) of the car. Remove the 10mm nuts holding the cover in place. Gently pry the cover off.

Remove locking ring

To remove the locking ring, you will need a flat-head screwdriver and a hammer. Use the screwdriver to turn the ring counter-clockwise. If it is stuck, gently tap the screwdriver with the hammer to help it along.

Replace filter

Step 1: Prepare for the task

Before starting, ensure you have the following tools and materials:

• A new fuel filter assembly with a gasket and O-rings
• A ratchet and 10mm socket
• A flat-head screwdriver
• A rubber mallet or hammer
• A plastic drop cloth or sheeting
• Lubricant (e.g. Vaseline)
• Eye and skin protection (e.g. goggles and rubber gloves)
• Needle-nose pliers or a thin picking tool to remove old O-rings

Step 2: Remove the rear seat

There is an access port to the fuel filter under the rear passenger-side seat. First, remove the rear seat to access the fuel filter port. The seat comes out in two parts. Remove the bolt between the two seats, close to the floor, to unlock the seats. Pull up on the locking mechanism to remove the back of the seat. You'll need to swivel the seat to get the other side out. Once the back is off, lift the bottom seat from the front edge, and it will pop right up and out.

Step 3: Locate the fuel filter housing

Once the seats are out, you will see the access panel for the fuel filter housing on the floor on the passenger side. Before starting your work, lay some plastic drop cloth around the housing to protect the fabric from absorbing any spilled fuel.

Step 4: Remove the filter assembly from the housing

Use a 10mm socket and ratchet to remove the nuts that hold the panel in place. Once the panel is off, vacuum or clean the area to prevent debris from falling into the filter housing.

The top of the fuel filter housing is secured with a locking ring. Use a flat-head screwdriver to turn the ring counter-clockwise and unlock it. Get a rag under the fuel line and disconnect it by pressing the tabs. Be prepared for some leakage and protect yourself and the area with shop rags.

Once the fuel line is disconnected, remove the lock ring and set it aside. Use a flat-head screwdriver to pry up the filter assembly a few inches, then grasp the top and twist while pulling up to remove it completely.

Step 5: Remove and replace the fuel filter and O-rings

Once the assembly is out, remove the old filter and O-rings. Use a turkey baster or old rags to soak up the fuel from the bottom of the housing to expose the lower O-ring. Remove both the upper and lower O-rings.

Apply some lubricant (e.g. Vaseline) to the new upper and lower O-rings before installing them. Grab the internal assembly inside the housing, insert the new filter, and twist it back and forth to get it to solidify in place.

Once the filter is in, you may need to pull up the assembly slightly from the housing to get the cap back in place. When installing the cap, push down and twist it in the opposite direction of removal to lock it in place. Drop the assembly back into the housing.

Your replacement kit will include a larger gasket ring that goes around the top of the assembly. Ensure you put it on in the correct direction, making sure it is completely flush with the edge of the housing.

Replace the locking ring, hand-tighten it, and then gently tap it with a hammer or mallet to ensure it is snug. Be careful not to strip it.

Step 6: Reassemble and test

Reattach the fuel line, wipe up any spilled fuel with your drop cloth, and dispose of it responsibly. Finally, replace the seats.

Before starting the car, turn the key in the ignition a few times to get the electrical system lit up, and then turn it off again. Do this a few times to get the fuel system re-pressurized.

Frequently asked questions