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Diesel Fuel Water Separator How it Works

FUEL SEPARATORS: Diesel becomes contaminated much easier than gasoline. That means you should drain any contaminants and water from a fuel separator.

It is a task most diesel owners can perform themselves but what exactly is a fuel water separator?

In simple terms a fuel water separator is a small filtering device. Its function is to ensure clean fuel gets delivered to the engine.

Why is the delivery of clean fuel important for an automotive diesel engine?

Without a fuel separator you lose effective protection for the engine. That also means a loss of protection to any marine or industrial engine applications.

How Do Diesel Fuel Water Separators Work?

The fuel separator filters and removes water and solid contaminants from the fuel. It must remove the water before it reaches the fuel pump to work effectively.

If the separator fails, any water in the fuel can wear away lubricants on the diesel fuel injectors. When the device removes contaminants and solid materials it helps prevent engine clogging.

Running a car with dirty fuel is a common reason for many diesel engine problems. In some cases it may cause complete engine failure. Common types of fuel separators include those used in diesel and marine engines.

Diesel Fuel Water Separator

Most diesel fuel water separators get made using aluminum materials. You can buy diesel fuel separators in various sizes depending on the type of vehicle you have.

Diesel Fuel Water Separator How it WorksAs a rule, you will need to drain a small diesel fuel water separator more often than a large version.

Either way, drain it regularly because there is a higher amount of water in diesel fuel than in gasoline.

Unfiltered water or dirt will create diesel engine inefficiency. Dirty fuel also contributes to high fuel consumption and an increase in engine wear and tear.

There is one more step to perform once the diesel fuel water separator collects filtered water. You should then drain the fuel filter during any routine vehicle maintenance.

Most modern diesel cars have a sensor which informs you when the water level needs draining. Removing the fuel tank drain plug allows collected water and dirt to flow out of the separator.

Note: Drain the separator often because they do not function well when they get too full.

Marine Fuel Water Separator

Manufacturers use plastic or aluminum material for making marine fuel water separators. Marine fuel filters draw out water from the boat fuel. That filtration system helps to prevent water entering the boat motor.

Having water present in a marine motor can cause a steam explosion and damage the boat cylinders. A marine fuel separator can be part of a primary filter or you can install it as a secondary filtration system.

Marine fuel water separators drain off water in one of two ways.

  1. The filter siphons off the water if the separator is part of a primary filter. The motor discards waste water along with contaminants using this method.
  2. Secondary filters use a siphoning mechanism to expel contaminants and waste water. Fuel and water get pumped into a filter and then get subjected to a rapid spinning motion. Unwanted contaminants and water sink to the bottom but the fuel stays at the top. It then gets siphoned to the fuel line. Waste water then gets drained off when necessary.

Some types of marine fuel water separators clean the boat motor exhaust system during the drainage. They work with the exhaustion system to clean it along with the fuel. In this case it is best to replace this type of marine fuel water separator annually.

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