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Fuel Filter: Diagram, Parts, Working, Types, Cleaning, Uses [PDF]

In this article, you will learn what is a fuel filter? Its diagram, parts, types, working, cleaning, advantages, and uses. Also, you can also download the PDF file of this article at the end. 

What is Fuel Filter?

In every type of car engine, the fuel system keeps gasoline or diesel in the tank and then draws it through the fuel lines and delivers it through the fuel filter to the carburetor or fuel injector. Then, it is supplied to the cylinder chamber where it is mixed with air and burned to generate energy.

It is an important part of this system as it protects the engine from harmful waste and is also known as a fuel strainer. As the name suggests, it is a fixed filter in the fuel line that detects dirt and rust particles and separates them from the fuel. It is usually built into a cartridge containing filter paper.

In modern cars, the filters are an essential part because modern designs include a tighter fuel system than engines from a decade ago. Unfiltered fuel may contain heavy contamination such as paint chips, dirt, rust, etc.

It must be removed to prevent quick damage and eventual failure of the fuel pump and injectors. The filters help to improve performance, because the fewer contaminants present in the fuel, the more efficiently it can be burned. In addition, they need to be maintained at regular intervals for optimum performance.

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Parts of Fuel Filter

Following are the main parts of a fuel filter:

  1. Housing
  2. Base plate
  3. Center tube
  4. End cap
  5. Compression spring
  6. Filter media
  7. Drain valve
  8. Water sensor
  9. Gasket
  10. Strainer
Fuel Filter Diagram

#1 Housing

This is the main housing that protects the internal components of the filter. The filter housing is usually made of steel and has pressure inside the filter and prevents it from overflowing.

#2 Base Plate

It is the end part of the housing where the device connects with the mounting assembly. This plate provides the installation of the interface, prevents fuel leakage, and maintains pressure inside the filter.

#3 Center Tube

It acts as a support for filtration and prevents it from falling inward. In addition to being a structural component, the tube serves as an outlet for the filtered fuel.

In order to withstand the pressures created by the differential in the filter, manufacturers make this part from a stronger material using steel.

#4 End Cap

The end cap is also a supporting structure that holds the filter media within a place. It is attached to the filtration media using adhesive, the end cap also works to prevent leaks.

#5 Compression Spring

It is an essential component that provides the compressive force to hold internal components under varying pressures.

#6 Filter Media

Filter media is the part that helps to trap particles or water and other particles. It can be made of cellulose or synthetic material. A filter media is designed to increase the area of the surface over which filtration takes place.

#7 Drain Valves

When fuel is present in the filter, the drain valve provides a mechanism for the fuel to bypass the filter media.

#8 Water Sensor

The main purpose of the water sensor is to detect the presence of water in diesel fuel and this sensor is fitted inside the fuel strainer. It has two main output signal stages, low level, and high level, which identify the presence and absence of water.

#9 Gasket

It is commonly referred to as a seal part of the filter. To properly seal the oil filter it uses an oil filter gasket that seals between the filter and the engine block. These are either made of rubber or paper and are important for keeping the oil inside the engine.

#10 Strainer

The strainer is the main part of the fuel filter which filters the fuel and keeps the particles out before they enter the fuel line. It is usually a plastic fabric woven in the shape of a tube with the ends heat-sealed closed.

Working of Fuel Filter in Your Car

The fuel system is consists of filters and screens to prevent dirt in the fuel pump and carburetor. Dirt causes, of course, poor engine performance, and prevents normal operation of fuel pump and carburetor.

Fuel Filter
Image: IndiaMart

The fuel is filtered when it enters the fuel tank. In some cases, it is again filtered in the fuel pump. This filter is located in some carburetors also. However, a separate filter is also connected to the fuel pump and carburetor. It filters the fuel before it enters the carburetor.

The figure shows you a ceramic-type fuel strainer. It is connected between the fuel pump and the carburetor. It serves to catch any water or foreign particles that were not filtered out in the fuel pump sedimental bowl and strainer or in the fuel tank filter unit.

The fuel entering the glass bowl passes through a ceramic filter which separates the foreign particles and the filtered fuel comes out from it. Finally, this water and sediments are collected in the bowl which can be removed for cleaning.

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Types of Fuel Filiter

Following are the main types of fuel filters:

  1. Diesel fuel filter
  2. Gasoline fuel filter
  3. Canister fuel filter
  4. Inline fuel filter
  5. In-tank fuel filter
  6. Cartridge fuel filter
  7. Carburetor inlet filter
  8. Pump-outlet fuel filter
  9. Spin-on fuel filter

#1 Diesel Fuel Filter

Diesel Fuel Filter

These types are usually made in the shape of a basin or bowl which means the filter shrinks down. In this the water is stored in the bottom of the bowl, while a valve at the bottom of the bowl allows water to drain from the basin, leaving only the water.

When taking a look at the chemistry of an engine, the water fraction-per-liter ratio is higher than that of a diesel. The difference in density is why the water accumulates in the bottom of the bowl and the diesel remains in the basin after the water is drained.

#2 Gasoline Fuel Filter

Gasoline fuel filters are most basic and are not complicated because they only have a few parts. In a fuel system, fuel is stored in a tank containing gasoline and is then drawn through fuel lines and delivered through a fuel filter to a carburetor or fuel injector.

This filter removes dirt and rust particles from the fuel, preventing them from entering the engine and causing damage. It helps to deliver clean gasoline to your vehicle’s engine while protecting the fuel injectors.

#3 Canister Fuel Filter

Canister Filter Type
Image: Amazon

This is a type of fuel filter that uses a canister that almost looks like a shell that contains the filtration element. Most filters are of this type, the housing can be made of plastic or metal, depending on a number of factors.

Canister fuel filters are considered to be less friendly to the environment. As soon as their lifespan expires, the entire equipment must be dismantled and thrown away, and a new one needs to be installed.

#4 Inline Fuel Filter

Inline Filter Type

These are mounted between the fuel pump and the carburetor which protects the carburetor from contamination but does not protect the fuel pump. These are usually made of plastic or metal containers with a pleated paper element inside.

In the event of installing this filter, care should be taken so that the gasoline flows through them in the direction marked by the arrow on the body. It has a bowl that acts as an in-line filter to clean the petrol. Water and other particles collect in the bowl and are removed through periodic cleaning of the filter.

#5 In-tank Fuel Filter

In-tank Filter Type

Filters of this type are used in most developed vehicles and are mounted in gas tanks. The In-tank filters can be taken apart or integrated into the in-tank fuel pump. One drawback of these types is their inaccessibility, which makes them difficult to service. This filter has a longer lifespan, which helps avoid breakdowns and towing call-outs.

When the fuel pump is part of the assembly, the in-tank fuel filter cannot be replaced separately, which means a more expensive replacement when you have to replace a damaged filter. It is a high-grade media that provides high throughput while protecting against pollution from dirty fuels.

#6 Cartridge Fuel Filter

A cartridge fuel filter generally consists of the filtration member, structural parts, and some essential filter parts. This type of filter does not have an outer shell. It has a metal or plastic housing which is a separate component that is mounted on the vehicle to a mating surface.

It can be used repeatedly, with only the cartridge being the disposable part. Cartridge fuel filters are environmentally friendly. With only a few metals or plastic parts thrown away when a filter goes bad, replacing this type of filter has less impact on the environment.

#7 Carburetor Fuel Filter

Carburetor Filter Type

Some manufacturers install a filter at the carburetor inlet. In carburetor type, the fuel filter can be found under the hood by looking at the fuel line from the carb to the rear. The filter is screwed into the carburetor fuel inlet and is clamped to the inlet hose at the other end.

#8 Pump-outlet Fuel Filter

Some types of automobile vehicles include fuel filters on the outlet side of the fuel pump. This fuel filter is installed in the fuel pump outlet tower while it is located under the pump.

#9 Spin On Fuel Filter

Spin On Filter Type

Typically, threads are required to mount a spin-on filter to a vehicle. These filters are usually installed in the engine compartment. It consists of several parts including a steel canister, drain-back valve, bypass valve, and a gasket.

This type of fuel filter is easy to replace, so it only requires dismantling the damaged filter and fastening a new one in its place. Apart from being just a simple task, almost any vehicle owner can do it.

How To Clean a Fuel Filter?

Before removing the filter, clean the filter body and cover.

Remove the center bolt to separate the filter body.

Take out elements from the filter body.

Fix the filter cleaning plug in the filter element so that the diesel, in which the filter is to be cleaned, may not enter the element through the holes in it. Because the diesel may consist of dust particles.

Fix up the plug.

Dip the element with a plug in the diesel tray and clean it.

Clean the element with a brush. Blow the air with your mouth in the plug pipe. It will remove the diesel from the felt.

Clean the body of the filter bowl.

Replace the rubber packing between the bowl and cover. Now, reassemble the filter.

Advantages of Fuel Filter

  1. This device prevents dust that could otherwise get into the engine and damage the main components such as cylinder, piston etc.
  2. Replacing the old filter can avoid such problems and ensure a longer engine life.
  3. A clean filter is essential as it can give you a better performing engine.
  4. This device helps to purify the fuel by eliminating fuel contaminants to keep the fuel flowing smoothly.
  5. A new fuel strainer can provide you better fuel efficiency.
  6. This device protects the fuel injectors and fuel pumps from dirty contaminants.

Disadvantages of Fuel Filter

  1. If your vehicle has a faulty fuel strainer, the vehicle will not start.
  2. If is clogged, it completely prevents fuel from flowing into the engine and the car simply will not start.
  3. A damaged strainer can cause low fuel pressure that result in poor fuel conditions and engine misfire.
  4. Also, a faulty strainer can result in poor fuel mileage and rough idling.
  5. Inaddition, a damaged strainer can give you erratic low-speed performance and engine delay.

Wrapping It Up

After reading our review on filters, you now understand why it is important to have quality in your car. This filter ensures the clean operation of your fuel stream in the fuel system and engine. Selecting the right type of filter is also part of the process as not all filters are alike.


So now, I hope I’ve covered everything about this topic. If you still have any doubts or questions on this topic, you can contact us or ask in the comments. If you like this article then please share it with your friends.

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Read more interesting articles like this:

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  3. How do you measure fuel in a tank with the help of a fuel gauge?

External Links:

  1. https://en.wikipedia.org/wiki/Fuel_filter
  2. https://what-when-how.com/automobile/fuel-filters-automobile/
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