How To Stop CO2 Airsoft Guns From Leaking (DIY Guide)

Gas guns are powerful and realistic in the way they move and feel. However, gas-powered guns often leak, which can cause the weapon to stop functioning as it should.

If your CO2 gun is damaged, follow these steps for a DIY repair guide:

  1. Get set up
  2. Find the leak
  3. Lubricate the seal
  4. Replace damaged or faulty o-rings 
  5. Tape the cartridge 
  6. Mend the valves

Keep reading as we explore how to fix your leaky airsoft guns so they can work flawlessly for years to come. I will also give you some tips and tricks that can prevent your CO2 guns from leaking in the first place. Let’s dive in. 

1. Get Set Up

As with any DIY task, you will need to have the right tools and equipment before you can get to work.

Here are the items that you’ll need to repair your leaky airsoft gun: 

  • Damaged Airsoft Gun
  • Water and Soap
  • Screwdriver
  • Silicone Oil/ Grease
  • Teflon Tape
  • Full Cartridge 

You likely already own the majority of items listed above. If some of them are missing from your toolbox, you can purchase them at your local hardware store. Many of these items are also available at airsoft supply stores and online retailers like Amazon. 

Once you have obtained the materials on the list, you are ready to go onto the next step: finding the source of the leak.

airsoft gun leaking co2
If you don’t feel too handy, then it is the best idea to take your gun to your local airsoft shop or even airsoft field, where they will be able to repair it.

2. Find the Leak

A leak in your CO2 gun is frustrating. Your airsoft pistol or rifle will not function as it should if it even works at all. Therefore you’ll be eager to get started on fixing your airsoft gun. 

The first step of mending your gas leak is to find the source. If you have a fast leak, you’ll likely be able to feel the air being released from the gun. If this is the case, you already know where the leak is coming from. 

However, slow leaks are much more common than quick ones. There are a couple of ways to find a slow leak. You first have to figure out whether gas is stored in the magazine or the gun itself. 

If the CO2 is contained inside the gun itself, you’ll need to use the water and soap method to find the leak. 

To do this, you must mix soap with a small amount of water. Then you spread this mixture around your gun. Make sure to apply your solution over valves and seals as they are the most likely sources of leaks. 

If the solution covers the gas leak source, bubbles will quickly appear as the air escapes through the soapy water. Therefore the source of the bubbles is the source of the leak. 

If the CO2 is stored in your airsoft gun’s magazine, you can quickly submerge the magazine into a bucket of water. The bubbles will appear from the source of the leak. 

Exercise caution when placing any airsoft guns or components in water as it does not mix well with airsoft equipment. 

3. Lubricate the Seal

If your a or soft gun has a slow gas leak, it’s most likely an issue with the seal. This seal will be around the pin that punctures the gas cartridge when loaded into the gun. In most gas-powered guns, this seal will be on the gun where the magazine fits. 

The function of the seal is to prevent CO2 escaping. To ensure that the seal functions correctly, you will need to apply lubrication. The ideal lubricant for this seal is silicone oil or silicone grease. 

A seal with silicone oil applied has a high lubricant absorbency which minimizes friction and wears. Silicone oils provide the seal with protection against environmental elements and wear and tear that can cause the seal to loosen. Silicone oil also offers protection against water and corrosion.

Using silicone oil on the seal of your CO2 gun will strengthen the seal and prevent leaks in the future. Silicone oil should be applied regularly to ensure your airsoft gun remains effective. 

Instead of using silicone oil, you can purchase a gas cartridge that contains lubricating oils. This eliminates the need for applying silicone to the seals. However, this variety of gas for your airsoft rifle will be more expensive than using regular CO2 cartridges and applying silicone oil yourself.

4. Replace Damaged or Faulty O-Rings

O-rings are the small doughnut-shaped rubber rings that you find in valves and seals. These rings keep the valve locked in tight to prevent leakage and allow air to enter from pressurized containers such as a CO2 cartridge. Sometimes the O-rings loosen, which can weaken the valve and seal. As a result, air can escape from the container. 

If your O-rings are damaged, you should not attempt to repair them. Once these small pieces have come loose or lost their shape, you will need to replace them. You can purchase O-rings from most hardware shops for a small fee. 

To replace the O-rings, find one that fits, remove the damaged ring and replace it with a new one. Once the new O-ring is in place, apply a generous amount of silicone lubricant to strengthen the seal. 

If you still leak your CO2 gun after replacing the O-rings and applying silicone lubricant, you should move to the next step: Applying tape to the cartridge.

5. Tape the Cartridge

Applying tape to the CO2 cartridges used in your airsoft gun is also an effective way to prevent leaks. The extra layer of tape surrounding the cartridge will create a tighter seal when the cartridge is punctured on loading. 

As a result, a tight seal is formed, preventing air from escaping through a loose seal. This prevents leaks and ensures that your gun can continue to fire without wasting gas. 

The ideal tape to use when sealing your cartridges is Teflon tape. Teflon is a solid and durable material, famously in bulletproof protective wear. You can purchase Teflon tape from any hardware store as the tape is commonly used in plumbing. 

To tape your CO2 cartridges, apply a thin layer of Teflon tape to the seal on the cartridge. Teflon tape is very thin and easily sticks to itself. Therefore application may be complex for you initially, but over time the task becomes more manageable and less time-consuming. 

Don’t worry about wasting Teflon take as it’s affordable, and you only require small amounts to provide an effective seal for your cartridge. 

For best results, apply five or six layers of Teflon tape. This will build up a firm deal that will contain the CO2 while the gun is in use. To ensure an adequate bond is formed, apply silicone lubricant to the tape once applied to the cartridge. 

While taping every cartridge, you will use a laborious and tedious exercise; you will not only prevent gas leaks in your gun but will also increase the lifespan of the airsoft weapon. 

Preventing CO2 from escaping from an airsoft gun will also improve the weapons performance and save you money on CO2 cartridges as your weapon will be much more efficient. 

6. Mend the Valve

If the source of the CO2 leak from your airsoft gun is the valve, you can attempt to repair or replace it, however; this is often a complex and expensive undertaking. 

If your valve has been damaged, you will likely need to pay to have the valve replaced. You can order a new valve yourself online. You need to know what size valve your airsoft weapon uses. To figure this out, search online for the valves used in the make and model of the airsoft gun that you’re fixing. 

Once you have the appropriate valve for your CO2 gun, you should remove the damaged valve from the magazine or gun. Valves usually screw out with a screwdriver. You can then install your new valve. Once your new valve is fit, apply a coating of silicone oil to strengthen the seal. 

Replacement valves for airsoft guns can be expensive. On top of this, if you do not release all of the pressurized gas from the weapon before working on the valve, a severe accident could happen. Therefore it’s best to leave more complex repairs to skilled professionals who know how to work with airsoft weapons safely.

However, hiring a professional to replace a damaged valve on an airsoft gun can be pretty expensive. In most instances, the cost of this is close to the price of a new weapon. Therefore, the majority of airsoft guns are not worth repairing when the valve stops working. 

Although, if your airsoft gun has sentimental value or is worth more than a few hundred dollars, it’s worthwhile paying for a professional to repair the damaged valve.

Video: How to Fix Leaking Co2 for Airsoft Guns

Preventive Measures

The best way of dealing with a leak in your airsoft gun is to prevent a gas leak in the first place. Preventive measures will prevent damages from occurring to your gas-powered weapon.

This will prolong the lifespan of your airsoft gun and save you a fortune on potential repairs and replacements. Here are a few effective preventive measures that you can take to ensure your CO2 airsoft gun continues to function effectively. 

Appropriate Storage 

One of the vital aspects of caring for your CO2 airsoft gun is storing the weapon in a way to prevent damages. Specifically, the magazine requires adequate storage to remain functional. 

To effectively keep your magazine, there are a few key things to remember. 

First of all, you should remove all of the bbs from the magazine. This prevents the springs from getting jammed or damaged while not in use. 

Next, you must apply a generous amount of lubricant to the seals, valves, and other exposed metal pieces. Use silicone oil or grease as this lubricant forms an effective and powerful bond that fights against leaks. 

You should also use a gas that contains lubricating elements designed explicitly for airsoft weapons. Only apply a small amount of gas when the gun is in storage but ensure that the magazine is not empty when not in use. This prevents damages to the seals and valves. 

Once you have put some maintenance gas into your magazine, apply another layer of silicone lubricant to o rings and seals to strengthen their hold. 

Apart from the tips listed above, the only critical point of storing your airsoft gun is to keep it somewhere dry, as water and moisture can severely damage the weapon. 


Airsoft guns, just like real finds, require care and maintenance to ensure that they function correctly. Maintenance for CO2 weapons is vitally important, yet it’s still easy and convenient to do. 

Keeping your CO2 gun clean and free from dirt will prevent the mechanisms from jamming. Duct and dirt may also block seals and calves, which can result in CO2 leaks and wear. 

To avoid these damages, make sure to wash your gun after every airsoft session. Use a tiny amount of water but do your best to remove all the dirt. 

Another critical aspect of maintaining a CO2 airsoft weapon is lubrication. CO2 dries out the fun as it passes through. This can cause jams, leaks, and damage. To protect your airsoft gun against this, apply silicone oil or grease regularly. 

Ideally, you should use lubrication every time you change the magazine; however, this may be unrealistic. 

Final Thoughts

CO2 airsoft guns are realistic, robust, accurate, and very enjoyable to use. However, they have one major flaw. Gas-powered airsoft guns are prone to leaking. This results in gas escaping from the gun, which is wasteful and harms the weapon’s performance. If your CO2 gun is leaking, follow these steps for a DIY fix. 

  • Find the leak.
  • Apply silicone lubricants to seals and valves.
  • Replace O-rings

To prevent any gas leaks in the future, regularly apply silicone lubricant to the valves and seals of your airsoft gun. Applying tape to the cartridges is another measure you can take to prevent CO2 from escaping.