Diesel fuel filters can be considered as the final defense for blocking particles that may be in the fuel from getting to the engine and damaging it. High pressure fuel injected systems with diesel can have additives or flecks of material that can get introduced into the system inadvertently. If left alone, these particles can cause significant damage in a short period of time, something that makes fuel filters very important to the overall performance of your vehicle.
There are different types of diesel fuel filters. There are those that are mounted under the car in the firewall, known as in-line fuel filters, and there are non-serviceable filters that are mounted inside the fuel tank, known as strainers. Generally, fuel filters are comprised of pleated paper or a mesh screen that is designed to pull flakes of sediment and water in case of diesel engine, and in doing so they sort these materials away from the fuel and make sure that they do not get into the engine. They are also not allowed back into the fuel tank to further contaminate the fuel. They are stored within the body of the filter itself
Good diesel fuel filters need to be changed every three to five years, or when you are getting a tune up done on your vehicle. But the in-line filters are somehow different because the time between changes is set by the manufacturer of your vehicle. When you keep your fuel filter working well, it means that you are keeping debris that are potentially disastrous out of the fuel before it can cause long lasting harm to the engine and other parts of your vehicle.