What Does The Anti Drain Back Valve Do On An Oil Filter?

What does the anti drain back valve do on an oil filter? The anti-drain back valve is a valve that is put on an oil filter to prevent oil from draining back down the filter when it’s not being used.

The valve is typically only used when a filter is being changed, but the valve can be used on the filter before the first use.

The anti-drain back valve prevents any oil exposed to air from being burned off, reducing wear and tear on an engine.

It also eliminates any potential carbon build-up, maximizing the fuel efficiency and performance of your car or truck.

Do You Need An Anti-Drain Back Valve In Oil Filter?

An anti-drain back valve is necessary for filters bolted into the side or top of the engine body. The little valve on the filter closes and prevents oil from draining back into the engine when you shut it off.

But for filters built into the oil pan, there isn’t a need for an anti-drain back valve. Many oil filters are built into the oil pan, so fitting a valve is easy. Some, however, are not.

The problem with an oil filter fitted on top of the cylinder head and with an electric cooling fan is that there’s no place to mount the anti-drain back valve.

I have never seen one fitted in this way — so all you need to worry about is whether it’s needed or not. I don’t think it is.

Anti Drain Back Valve Purpose

The anti-drain back valve covers the openings where contaminated oil enters the filter. The anti-drain back valve’s primary function is to stop oil from leaking out of the filter when the engine is turned off.

When the engine runs, it stops the oil from passing back into the crankcase, saving the oil-pressure sensor and other power train components.

What Is Oil Filter Anti Drain Back Valve?

An oil filter anti-drain back valve is a safety device that helps to prevent oil from backing up and flooding the engine.

By design, the oil filter prevents dirt, rocks, and other objects from getting caught in the engine’s oil filter and eventually clogging it up.

This can cause the engine to fail prematurely by preventing oil from reaching its bearings and other vital components.

When the oil temperature is low, it’s ideal for keeping the oil filled in. However, when the engine is performing an activity that generates high heat, like braking or running at a high RPM, leaking oil into the engine can cause damage to it.

This can result in engine failure and even fire. If this happens regularly, it may be time to look at another option for filter replacement.

What Is A Drain Back Valve?

A drain back valve is an important part of an oil filter system. It allows oil to flow back into the engine while the engine is still running, preventing dirty oil from entering the engine.

A drain back valve is often needed on engines with high oil consumption rates or when there is a lot of debris in the oil. A drain back valve is connected to the oil filter cap and operates like a faucet.

When the fan spin speed increases, the pressure in the oil filter rises and turns on the valve. This allows oil to flow back into the engine, preventing debris from entering it.

What are its benefits? A drain back valve improves engine performance by preventing debris from entering the engine.

It also prevents dirty oil from entering the engine, which can cause decreased fuel economy and wear on equipment.

Where Is The Anti-Drain Back Valve?

The most common configuration of this valve is a rubber membrane attached to the inside of the spin-on filter cover. This membrane covers the pores that allow contaminated oil to enter the filter.

The pressure relief valve is there to prevent the drain back pressure from harming onboard system components. When the engine oil is low and the engine needs to be restarted, this valve opens to allow some oil back into the engine.

This protects internal components such as camshafts, lifters, and pistons from stress caused by bad oil. When the engine is once again running with good oil levels, this relief valve closes.

What Happens If The Bypass Valve Is Open In The Oil Filter?

If the bypass valve is open in the oil filter, the oil will flow back into the engine, causing damage. The oil filter prevents this from happening by trapping the gunk that has built up on the screen.

An anti drain back valve will close and stop the flow of oil when the bypass valve is open. So what happens if it is not there? Any gunk on the screen will be sucked back into the engine and cause damage.

The porosity of the bypass valve determines how much viscosity oil can flow through and how much pressure can be held back.

This is a very important part of your engine as it may save your engine from experiencing costly damage. Most oil filters have a bypass valve in them, but some do not, and you should check before purchasing one.

Can You Drive Without Oil Filter Bypass Valve?

The answer to this question is that you can technically drive with an oil filter bypass valve installed, but you will have to take extra precautions to keep your engine running smoothly and avoid engine slippage.

The purpose of the anti-drain back valve is to prevent oil from flowing back into the engine when the filter has been properly replaced.

If the anti-drain back valve fails, then oil will continue to flow back into the engine, potentially leading to serious engine damage.

As an example, the oil filter bypass valve is designed to relieve pressure in the engine’s oiling system.

If a standard oil filter replacement is performed and there is a problem with the anti-drain back valve, then the engine will not have any way of relieving its pressure and will keep building up.

This could be catastrophic, so precautions must be taken when driving a vehicle with an oil filter bypass installed.

Is A Bypass Oil Filter Worth It?

The anti drain back valve is a safety feature built into most oil filters to prevent unwanted oil drain back (i.e., when the engine loses oil pressure and attempts to suck air into the engine instead of oil) and subsequent engine damage.

While it’s always worth upgrading to a bypass filter, there are some situations where a traditional filter may still be adequate. Here are four reasons why a bypass filter is always worth it:

1. Prevention of oil drain back 

If your engine experiences an issue with oil pressure, the anti-drain back valve will prevent the engine from drawing in air, which would cause the engine to lose oil pressure and potentially damage it. A bypass filter will always protect against this.

2. Removal of bigger contaminants 

A traditional filter will trap small particulate matter and other contaminants, but a bypass filter will also remove larger particles and debris that can cause damage over time.

This is particularly important if you have any older vehicles with low-quality oils or if you regularly drive in dusty conditions.

3. Extended engine life 

By removing larger debris and contaminants from your engine, a bypass oil filter will help extend the life of your engine by preventing wear and tear on critical components.

4. Increased protection 

A bypass filter is capable of higher flow rates, allowing it to provide more effective oil filtration than a traditional oil filter.

This is particularly important if you have an older car with a small chassis or excessively tight oil filters, which may not be able to handle the additional pressure produced by a bypass filter.

What Is The Difference Between A Bypass And A Full Flow Filter?

A bypass filter is a type of filter that bypasses the engine’s crankshaft oil delivery system. It does this by installing in between the oil pan and main engine oil pump.

The engine oil filter then sits on top of the bypass filter. This type of filter does not require the use of a draining back valve, as the excess crankcase pressure forces the dirty oil through the bypass filter and out of the engine.

On the other hand, a full flow filter relies on a draining back valve to divert crankcase pressure back towards the engine. This allows easier serviceability and improved cleanliness of the crankcase.

What Is A Full Flow Oil Filter?

A full flow oil filter is a type of filter that uses a cage or baffle to trap large particles before they can enter the engine.

This type of filter is typically found in high-performance engines because it allows for a higher flow of oil and prevents smaller particles from being deposited on the engine.

The anti drain back valve on an oil filter works to prevent the accumulation of oil on the valve, decreasing the chance of clogged filters.

A full flow filter is typically found on high-performance engines. These filters use a mesh screen that allows small particles to slip through and enter the engine.

Full flow filters are cheaper and easier to clean than some alternatives, but these filters are not always ideal for long-term use in an engine.

Full flow oil filters cannot withstand prolonged use in high RPM engines because they can accumulate wear particles which will destroy the filter itself.

Why A Full Flow Filter Is More Efficient Than The Bypass Type Filter?

An oil filter is a device used in an engine to remove particulate matter and other contaminants from the engine oil. Over time, wear and tear on the filters can cause them to become clogged with particles.

When this happens, the engine may not be able to run properly because the oil will not flow through the filters effectively. 

The best way to prevent this from happening is to change the oil filter regularly. One of the most common causes of an oil filter becoming clogged is improper maintenance.

Over time, sediment and other debris can build up inside the oil filter, resulting in reduced flow and obstruction. 

This is where a full flow type of filter comes into play. A full flow filter removes larger pieces of debris than a bypass type filter, meaning that it remains effectively clean even after being used for extended periods. Doing this reduces the chances of your engine running poorly, thanks to a clogged oil filter.

Frequently Asked Questions

1. How does the anti drain back valve work on a car?

Most oil filters have an anti drain back valve to prevent oil from flowing backward out of the filter when the car is being driven.

This valve’s job is to stop the flow of oil if the filter gets too full and can no longer filter properly. If you ever experience a stoppage in your oil flow, your anti drain back valve is likely not working properly.

2. Are anti drainback valves on oil filters a good thing?

Yes, anti-drain back valves are a good thing. They prevent the oil in your car’s engine from draining out of the filter and back into your engine, which can cause it to overheat.

The anti-drain-back valve on an oil filter regulates the flow of oil by opening when suction is applied to the valve, e.g., when you unscrew it and closing when there is no suction on it.

3. What causes the anti-drain back valve to fail?

Heat and contaminated oil are the main culprits which make the anti-drain back bulb fail. The anti-drain back valve fails when it is exposed to excessive heat or contaminated oil.

The most common cause of this is when the oil in the engine is low, and not enough oil comes back through to lubricate the gears.

4. What is the purpose of the oil drain valve?

The sump drain plug on an engine is replaced with a simple mechanism called an oil drain valve. They enable the beginning and end of the flow of oil by the use of a lever or other mechanisms. A sufficient piece of hose may usually be connected to most.


Surely you have the answer: What does the anti drain back valve do on an oil filter? Anti-drain back valves prevent the oil in your engine from draining out of the filter and back into your engine, which can cause it to overheat.

Most vehicles with electronic oil now use a filter that does not have an anti-drain back valve, as all the engines have a built-in module that closes the oil drains if the oil pressure drops.

However, if you are working on your vehicle and drain out all of the oil, it is possible to refill with oil and then crank over your engine without running. This may cause damage to your engine, as it will be putting power through an empty filter.

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