Replacing the fuel filter is part of regular vehicle maintenance. Keeping the fuel system in good condition by changing the filter will extend the life of the fuel pump. The impurities in the fuel that the filter retains will build up and clog over time making it operate inefficiently. A clogged filter reduces the pressure and volume of fuel in the system. If the vehicle loses power, the likely cause is a clogged fuel filter. Replace the filter at the interval recommended by the manufacturer.
Note: this article applies only to gasoline-fueled vehicles. The fuel filters of diesel cars and trucks are usually much larger, and the entire fuel system is more complicated. Diesel engine fuel systems also bear a lot of pressure, with modern common rail systems producing over 1,000 kg/cm2 of pressure. If this high pressure is released accidentally, you could be seriously injured.
Step
Part 1 of 3: Relieve Pressure on the Fuel System
Step 1. Locate the vehicle fuse box
To reduce fuel system pressure, you need to start the vehicle briefly while the vehicle's fuel pump is not working. To prevent the fuel pump from starting the engine, you will need to find a fuse box containing the fuel pump fuse. Read the user manual to find the right fuse box.
- If you don't have the user manual, try visiting the vehicle manufacturer's website.
- The fuel pump fuse is usually located in the interior of the vehicle.
Step 2. Remove the fuse for the fuel pump
After locating the correct fuse box location, use the diagram on the fuse box cover or in the manual to identify the fuse that powers the fuel pump. Use spout-tipped pliers, or plastic tongs to remove the fuse.
- While the fuse is blown, the fuel pump will not work when you start the engine.
- There is still residual fuel and pressure in the ducts that extend from the rear to the front of the vehicle.
- Browse the vehicle manufacturer's website to find a fuse diagram, if one doesn't exist.
Step 3. Make sure the vehicle gear is not in
Although the engine will not receive a fresh supply of fuel from the gas tank, there will be enough fuel left in the lines to start and start the vehicle briefly. Make sure the vehicle is in parking mode for cars with automatic transmission, or in neutral and the parking brake is engaged for vehicles with standard transmission.
- Even if it only turns on for a short time, the vehicle will still move if the gears are in.
- Make sure the parking brake is applied if the vehicle is a standard transmission. This step is optional but recommended for automated vehicles.
Step 4. Start the machine
Insert the key into the ignition (ignition) and turn to start the motor. The engine starts easily because it uses up the remaining fuel in the system and passes through the fuel pump.
- If the engine starts and then hisses, it is likely that the vehicle does not have sufficient pressure in the lines to push fuel into the engine.
- When the engine stops, the fuel pressure will be released sufficiently.
Step 5. Leave the engine running for 1 minute before turning it off
Depending on the fuel system in the vehicle and its average fuel consumption, the length of time the vehicle can function without a fuel pump can vary widely. However, the vehicle does not need to start until it is off. Just leave it on for 1-2 minutes before turning off the engine.
- Without a working fuel pump, the pressure in the fuel line will be released quickly.
- Leaving the engine running until it stops will make it difficult to restart.
Step 6. Replace the fuel pump fuse
While pressure is released from the fuel system and the engine is off, you can reinsert the fuse that powers the fuel pump. Put the cover back into the fuse box and return all previously removed components to access the fuse.
- Make sure the vehicle is switched off before replacing a removed fuse.
- Do not restart the engine after inserting the fuel pump fuse.
Part 2 of 3: Removing the Old Fuel Filter
Step 1. Disconnect the battery
Now there is no reason to restart the engine until the project is complete. Therefore, disconnect the negative terminal on the battery. Disconnecting the cable from the negative terminal will prevent the machine from starting while you are working. You will need to use your hands or a socket wrench to remove the screw that secures the wire to the negative terminal, but the bolt does not need to be completely removed.
- Disconnecting the battery will ensure that the engine cannot be started during this project.
- Set the negative wire aside to make sure it doesn't accidentally touch the battery terminals.
Step 2. Find the fuel filter
There are two common locations for fuel filters mounted in vehicles so we recommend reading the user manual to help locate them. Usually, on modern vehicles the filter is in the engine bay on the line leading to the fuel rail.
- Some vehicles may place the fuel filter in another location so consult the user manual for this.
- For some vehicles, you may need to access the fuel filter from inside the cab.
Step 3. Jack up the car if needed
If the fuel filter is on the underside of the vehicle, you will need a jack to access it. Slip the jack under the car at one of the jack points, then pump or turn the handle to raise the vehicle (depending on the jack type).
- After the vehicle has been jacked up, place the jack stand under it before working under the vehicle.
- Never rely solely on a jack to support the weight of the vehicle, especially if you will be working under it.
Step 4. Place the bowl or bucket under the fuel filter
Even if the pressure is released from the fuel line, there is still some fuel left in there which can spill out when the connection is removed from the fuel filter. Place a bowl or bucket under the fuel filter to catch any escaping or dripping fuel.
- If you are going to recycle, do not mix fuel with oil or coolant. Gasoline must be stored in its own container until it is deposited at a recycling center.
- Be careful when using plastic containers to hold gasoline as these can "eat" some types of plastic and cause leaks.
Step 5. Remove the clip that clamps the fuel filter
Most fuel filters are held in place by two plastic clips. Locate the clips on both sides of the fuel filter and use a flat head screwdriver to remove it from the hole. These clips can break so it's best to prepare a replacement clip.
- The clips that clamp the filter are made of thin plastic and tend to break easily. If you can remove it without breaking, these clips can be reused.
- You can buy a replacement filter at a repair shop.
Step 6. Remove the fuel line from the filter
While the clip is released, slide the fuel line off the filter to pop it from the nozzles at both ends. Be sure to point the end of the fuel line toward the bowl or bucket to catch the escaping fuel.
- Wear goggles and protective gloves during this part of the project to protect against petrol splashes.
- Try not to spill gasoline on the ground.
Step 7. Slide the fuel filter out of its bracket
The fuel filter is held in place by a metal bracket that encloses the outer casing. Once the fuel line is disconnected, you can slide the filter out by pressing it toward the front of the vehicle. This filter has a bell-like shape so it can only be shifted in one direction.
- If the filter is installed differently, you can slide it behind the vehicle until it comes off.
- Some of the fuel filters under the hood can be held in place by brackets using bolts that need to be removed in order to remove the filter.
Part 3 of 3: Installing a New Fuel Filter
Step 1. Compare the new filter with the old one
Before installing a new filter, compare it to the one you just removed. Make sure the outside diameters are the same, the nozzles are the same size, and the new filter fits snugly into the bracket.
- If the fuel filter does not match, you will need to return a new filter to exchange it for the correct one.
- Do not try to use the fuel filter for other uses in the vehicle as it will not be able to filter the correct amount of fuel.
Step 2. Slide the new fuel filter into the bracket
The new fuel filter should fit easily into the bracket. If you have to force it, chances are the diameter is wrong. The fuel filter should stop when it is installed properly because it can only be shifted fully in one direction.
- Be careful not to damage the filter casing as this may cause leakage.
- If you feel that you are pressing too hard to get it to fit, it's likely that the filter doesn't fit.
Step 3. Tighten the fuel filter on the fuel line
Slide the fuel line to the front and back of the filter, just as it was connected to the old filter. If the fuel line is already attached to the filter, slide a plastic clip through the fuel nozzle hole to secure the line connection to the fuel filter.
- If the clip breaks when it is inserted, do not use the vehicle until it is replaced.
- Make sure the fuel line fits snugly with the fuel filter nozzle before sliding the clip in.
Step 4. Lower the vehicle from the jack stand
Raise the jack to release the vehicle's weight from the jack stand, then slide it out from under the vehicle. Once the jack stands are free, lower the vehicle to the ground by releasing the jack pressure or turning it counterclockwise, depending on the type of jack you have.
- Make sure the jack stands are completely free so they don't fall over when the vehicle is lowered.
- Once the vehicle is safely down on the ground, reconnect the battery to complete the project.
