The Ultimate Guide To Changing Diesel Car Fuel Filters

Changing the fuel filter on a diesel engine is a critical aspect of vehicle maintenance. Diesel fuel tends to be quite dirty, and a clogged filter can lead to engine breakdowns, stalls, and other issues. Most diesel vehicles have two fuel filters: a primary filter that provides initial cleaning and a secondary filter for a final clean before the fuel reaches the injectors. Changing these filters is a moderately difficult task that can be done by diligent DIYers or professionals. This involves locating and removing the old filters, ensuring no spills occur, and installing the new filters correctly. The frequency of filter changes depends on various factors, but it typically ranges from 10,000 to 25,000 miles. Proper maintenance of diesel fuel filters is essential to ensure the smooth operation of your vehicle and prevent more significant issues down the line.

How to Change Diesel Care Fuel Filter

Locate the primary fuel filter

To locate the primary fuel filter, you will need to jack up your car to access it. The primary fuel filter is typically located somewhere on the fuel line between the fuel tank and the engine. It should be underneath the vehicle. Place an oil drain pan directly underneath the filter to catch any excess fuel.

The primary fuel filter is usually attached through fittings. Use a wrench or screwdriver to loosen the filter's fittings. If your filter is not attached through fittings, simply unclip the filter brackets to detach the filter.

Before starting, refer to your vehicle's manual to locate the primary fuel filter.

Remove the primary fuel filter

The primary fuel filter is typically located between the vehicle's fuel tank and engine. You may need to jack up the car to access the filter. Place a container underneath the old filter to prevent any spillages from excess fuel. If your filter is attached through fittings, use a wrench or screwdriver to loosen the filter's fittings. If not, unclip the filter brackets to detach the filter. You could use tape or caps to temporarily cover the fuel line to prevent further spillages during the transfer.

The primary fuel filter is usually held in place by two plastic clips. Locate the clips on either side of the cylindrical fuel filter, then use a flat-head screwdriver to pop them out of the holes. These clips may break as you remove them, so purchasing replacement clips along with your new fuel filter is advised.

With the clips removed, slide the fuel lines away from the filter to pop them off the nozzles at either end. Make sure to tip the fuel lines toward the bowl or bucket to catch any spilled fuel. Wear eye protection and gloves to protect yourself from fuel splatter.

The fuel filter is likely held in place by a metal bracket that wraps around its outer housing. With the fuel lines disconnected, you can slide the fuel filter out of the bracket by pushing it toward the front of the car. The fuel filter will have a slight bell shape, allowing it to slide out in only one direction.

Install a new fuel filter

To install a new fuel filter, first, clean the inside of the housing and the sealing surface with a clean cloth. Then, place the new O-ring that comes with the replacement filter onto the cap. Ensure it is correctly seated and secure. Next, place the new filter inside the cap and secure both inside the housing. Tighten by hand, then finish with a torque wrench.

It is important to note that the O-ring must be properly installed to prevent fuel filter leakage. Check your vehicle manual for specific instructions and torque specifications.

Now, turn your attention to the secondary filter, which is usually located under the hood, near the engine. You may need a square drive or socket to loosen the cap. Once the cap is loosened, remove it by hand and pull out the dirty filter. To avoid a mess, slowly lift the cap with the dirty filter still inside and hold it for a minute to let the fuel drain back into the housing.

Wipe down the filter cap and the sealing surface on the housing. Also, wipe down the inside of the cap and the thread surface. Remove the old O-ring from the cap with a pry tool or flathead screwdriver. Install the new O-ring, ensuring it is correctly seated.

Finally, install the new secondary filter into the housing and tighten the cap by hand. Finish tightening with a torque wrench to the manufacturer's specifications.

After installing both new filters, check for leaks and ensure your engine starts properly.

Replace the secondary fuel filter

The secondary fuel filter is usually mounted on the engine and close to, and immediately after, the lift pump. The engine-mounted secondary filters are on the pressure side of the lift pump, while the primary filter is on the suction side.

Place oil-absorbent sheets or pads under the filters.

Loosen the central bolt and remove the bottom bowl, then drop the filter. This type of filter may have a bowl that separates from beneath the filter element. The wall of that element may also serve as part of the containing wall for the filter. There may be a lot of fuel spilled, so be prepared. If you have more than one secondary filter, repeat the process.

Remove the O-ring seals from the grooves in the top carrier and the bottom bowl, then wipe the seating surfaces with clean paper towels to remove any dirt and debris.

Install new O-ring gaskets after smearing fresh clean fuel on their surfaces, making sure they're correctly seated.

Mount the new filter and screw the assembly together, making sure not to overtighten the bolts.

Check your work, then reopen the fuel petcock (if fitted). Bleed air from the fuel system. The process of bleeding varies with the particular engine. Consult your manual.

Start the engine and check for leaks. If the engine fails to start, you may have an air leak at the primary filter or on the suction side of the lift pump. In this case, check your work again. Often an air leak is due to incorrectly assembled filter components, or you may need to bleed the engine again.

Dispose of old fuel filters

It is important to dispose of old fuel filters properly. Fuel filters cannot be disposed of by simply throwing them away or sending them to a landfill. They must be drained and recycled, or you may face fines for improper disposal.

Firstly, drain the fuel from the filter. Turn the filter upside down and drain the fuel into an airtight container. If you are a business, you can take the waste to a hazardous waste collection site. If you are an individual, you can dispose of the waste in the garbage after allowing the filter to dry out for two days.

If you are unable to drain the fuel from the filter, take it to a household hazardous waste collection site. Alternatively, you can put the filter in a chemically resistant bag, seal the bag, and suspend it in a bucket using fishing line. Then, mix up some concrete, pour it into the bucket, and let it cure. Wrap the resulting concrete block in plastic and take it to your local hazardous waste location.

Another option is to cut open the filter and throw it away after draining the fuel. This allows you to see how dirty your fuel was. You can also let the filter sit outside in the sun for a couple of days to allow the gas to evaporate before throwing it away.

Remember to always dispose of fuel filters properly and follow any local regulations or guidelines to avoid any negative environmental impact.

Frequently asked questions