How Often Should You Drain Fuel Water Separator? (Find Out Now!)

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In the middle of the road in the desert in my RV, I noticed the light of the fuel-water separator light up. When I first bought my RV, I was told to keep an eye on my fuel-water separatorBut it had crossed my mind before my journey to check on it. Now that it has been lit, I am scared that my engine might be getting damaged.

But hearing this now, you might be wondering “how often should you drain fuel water separator?” The answer is, that you can drain it when the light has turned on. In many cases, this might be the only option. The light lights up when the water filter is filled more than 6.76 FL oz. You can set a rule of your own where you drain it every 10,000 miles.

That being said, if your light has gone off then you are in the right place. Keep reading this article to learn more about draining fuel-water separators.

Have you ever wondered How Often Should You Drain Fuel Water Separator?

Fuel Water Separator Be Drained

While the advance notice light illuminates or a notification appears in the data display prompting you to deplete the water separator, you should empty water from the module gathering. This occurs when approximately 6.76 fl oz (200 ml) of water accumulates in the module. If you allow the water level to rise above this level, the water may enter the engine and damage the fuel infusion hardware.

However, you may drain it by changing the gasoline filter every 10,000 miles. As a result, regular use and purchasing of fuel from high-volume dealers will reveal that water will not emerge in the fuel. You can also keep the tank as full as possible so that wetness doesn’t form as a result of accumulation in that state of mind from shifting climatic circumstances.

Sierra International 18-7982-1 Marine Fuel Water Separator Kit, white
  • All filters flow at 90 GPH to feed even the hungriest motor
  • Prevent damage to sensitive inboard, sterndrive and outboard fuel injection systems
  • Sierra fuel water separators remove over 99.8% of emulsified water from your gasoline

What happens if you fail to empty the fuel water separator?

Many individuals are aware that water and gasoline do not mix. But what happens when water gets into your fuel structure and goes unnoticed? Rust, erosion, and a large sum of money out of your pocket.

Avoid allowing water access to your fuel foundation. Water accumulation and saturated gasoline filters can cause significant damage to your internal engine parts that are not covered by your warranty. True, if you stick to your vehicle’s maintenance schedule, you can avoid a lot of these troubles.

Essentially, a dirty and waterlogged gasoline filter will have an impact on the performance of your engine. Water formation hinders the fuel filter from separating the harmful particles in your gasoline. These particles will accumulate in your fuel framework and motor, causing damage to those components.

The best strategy to resolve this issue is to ensure that you replace this part based on the scenario. Skipping the standard support on this might cause greater harm to the overall fuel structure.

Water left ignored in your fuel framework will cause long-term harm. There are two plans in place to prevent this from happening. To begin, respond quickly whenever the “Water in Fuel” advance alert light or message illuminates. 

Second, make sure you stick to your motor’s maintenance schedule. Ensure that the new parts are of high quality; nonetheless, an improperly made substitution filter might cause more harm than benefit. For that purpose, it is recommended that OEM parts be used wherever possible.

How might I locate the location of my filter?

fuel water separator diagram

A full water separator indicates that water is currently flowing into your fuel system. This water promotes erosion throughout the structure, including the internal move siphon. This siphon will thereafter corrode and is no longer covered under warranty. 

A corroded exchange siphon will not fill in as needed to maintain your fuel framework running at full capacity. Long term, this will result in considerable motor dissatisfaction and a slew of costly repairs. You may be wondering where the area of your filter maybe? On certain models, the module filter is located at the front of the gas tank or at the front of the rearward hub gas tank.

Cab Type

Box Length

Filter Location


8 ft (2.4 m)

The left side of the fuel tank.  

Super Cab

6.75 ft (2.057 m)

8 ft (2.4 m)

In front of the fuel tank.  

Super CrewCab

6.75 ft (2.057 m)

8 ft (2.4 m)

Left side of the fuel tank.  

How to Re-Prime After Draining a Water Separator?

Even if the gasoline system seems fragile, expecting a light to turn on is a bad idea. It’s possible that by then it’ll be too late to turn back. However, it won’t harm anything unless you choose to do nothing after the WIF filter has been exhausted.

If air is allowed to enter the fuel system, the motor will naturally release any trapped air. Prior to starting the engine, prepare by turning the way on for 30 seconds before shutting it off again. Repeat this several times. While there is air in the structure, the motor may perform poorly and emit white smoke. This is typical.

You might also need to review the overall set of instructions for maintaining the fuel conditioner, also known as the water separator or filter module. Additionally, you have a variety of options. The ideal approach is to first string on your fuel or water separator before filling it with the appropriate gas or pre-blend. Nevertheless, it depends on your setup.

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How Does Water Affect Your Engine?

When water enters the chambers, hydro locking occurs, disappointing the motor. Water provides a strong barrier against pressure. If water is allowed to enter the chamber, the driving rod will inevitably move the cylinder, but it will seek out water rather than an air-fuel mixture. 

To reduce energy waste, manufacturers compress the cylinders tightly inside the chambers. Therefore, the compressed water won’t have anywhere to go. Nevertheless, the energy needs to go somewhere. If you’re lucky, the motor will stall and come to a halt. If you’re not very lucky, pieces of the blazing chamber may start to fly. 

Strong motors cause the associated poles to twist or break, which causes them to blast holes in your motor. Through the air intake of the vehicle, water aids in the chambers. It may work out if you travel through a congested area of the road or, on the other side, if you awaken to find a river instead of your front road.

iFJF R12T Fuel Water Separator Marine 120AT NPT ZG1/4-19 Automotive Parts with Fitting -Complete...
  • Please tighten the filter by yourself when installing it.Please fill the filter with fuel when installation.
  • High Performance: Filters are designed for high performance applications,and with flow rate of 15 GPH on the R12T model. Remove water and particles down to 10 microns in size,ensures that fuel arrives at your engine clean and water-free with its advanced high-capacity filter media.Provides best protection to your engine and improve its performance.
  • Durable Materials: The filter housing is coated with a durable, corrosion-resistant electrostatic powder coating for superior surface quality. It can operate stably for a long time in harsh ocean or lake environments.

Why Is Draining The Water Separator And Fuel Filters Important?

Knowing how to drain water from fuel filter diesel is absolutely essential. In essence, your engine’s performance will be impacted by a dirty and soggy fuel line. The addition of water prevents the fuel route from filtering out the awful fuel particles. These particles will grow in your fuel system and motor, damaging those components. But if you are still wondering why it is important, take a look at the list below:

  1. Corrodes in motors.
  2. Operates as a purifier.
  3. The efficient fuel flow throughout the vehicle.
  4. Regular fuel filter replacement ensures that your motor receives clean gas.
  5. Increases the energy efficiency of your car.

How often should the fuel/water separator be replaced?

Replacing will get rid of the clogged fuel filter. Whatever kicks things off, whether it’s a season or 100 hours, filter it. If the engine in your car starts acting up, the first thing you should do, whether it takes 100 or 50 minutes, is changing the filter. No one can tell what kind of poop you just placed in your tank at the corner store, which is the reason.

Sierra International 18-7982-1 Marine Fuel Water Separator Kit, white
  • All filters flow at 90 GPH to feed even the hungriest motor
  • Prevent damage to sensitive inboard, sterndrive and outboard fuel injection systems
  • Sierra fuel water separators remove over 99.8% of emulsified water from your gasoline

How Can a Fuel-Water Separator Be Maintained?

Understanding how to keep up with the separator is crucial. As you are aware, a dirty separator cannot function as intended, further polluting the oil. Your motor is more susceptible to corrosion as a result. So, look at the steps below to know how to properly take care of your fuel-water separator:

  1. Verify whether there is consistent and comprehensive support for water aggregation.
  2. Apply a little oil to the fixing ring when you replace the filter component, and once it is fully in contact with the filter seat, tighten it by 3/4 to 1 turn the hard way.
  3. Check for oil leaking by starting the engine.
  4. After the water is discharged, don’t forget to add the oil.
  5. Concentrate on protecting the oil-water separator in cold climates.

Frequently Asked Questions

1. How often should I empty my diesel fuel filter, in your opinion?

You should empty it every 10,000 miles.

2. Could a water separator ever run out of water while the engine is running?

It is absolutely possible.

3. Is my fuel water separator supposed to be full?

Yes, it is important to make sure the fuel-water separator is filled.

4. How long is the lifespan of a fuel water separator filter?

It depends on the quality of the fuel.

5. How may water be removed from a fuel water separator?

The separator separates it by reducing lubrication.

Final Verdict

Over thousands of vehicle owners, every year don’t know how often should you drain fuel water separator. This important matter has been laid under the radar for these thousands of owners. Even though you were one of them, now you are not.

It is absolutely essential for a person to know how you should drain the fuel-water separator, your separator works as a purifier. Not cleaning it will cost you your precious vehicle. Now if your light is on, turn it off immediately following this article. Good luck!

Eric Weldon
Eric Weldon
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