How to Fix a Nail Gun That is Leaking Air (From the Trigger, Exhaust, or Top)

Why is my nail gun leaking air from the trigger?

Your nail gun is leaking air from the trigger because the O-ring rubber has worn out, or the trigger valve is damaged due to wear and tear.

Damaged O-ring

The O rings on the trigger valve keep air from leaking and affect the nail gun’s effectiveness. O-rings are often constructed of rubber or synthetic rubber. They are designed to seal the space around the head valve, preventing air from entering while allowing the cylinder to work correctly. When the O-ring wears out, it will no longer be able to keep the nail gun from leaking air from the trigger.

It’s essential that you replace the O-ring to avoid further complications. You can check our simple guide below on how to replace the O-ring.

Damaged valve

When you pull the trigger, the air is released, which causes the piston/driver assembly to press down on the nail, forcing it into the material. If you feel air leaking around the trigger, the trigger valve has become damaged. This is usually caused by the wear and tear of repeatedly pulling the trigger.

In that case, you’ll need to replace the trigger valve. You can follow our simple DIY steps below on how to replace it. However, you must follow your owner’s manual guide when replacing it.

How to fix a nail gun that is leaking air from the trigger?

You can fix a nail gun that is leaking from the trigger by replacing the O-ring or replacing the trigger valve.

Replace O-ring

When your nail gun starts leaking air from the trigger, the O-ring is probably damaged and it needs to be replaced. Here is how to replace it;

Note: To replace an O-ring, you need to buy an O-ring kit. This kit comes with the necessary equipment and lube you need for your replacement.

Unscrew the four bolts on the nailer top with the hex key or Allen wrench. Remove the old gasket.
Remove the grommet on the trigger’s side and drive the pin or pins out. Take out the trigger.
Some trigger valves are threaded into the housing, while others use roll pins to keep them in place. Depending on your model, use a wrench or tap the pins out.
Clean the inside of the housing.
Replace the outer O-ring and oil it lightly.
Remove the inner O-ring and replace it with the new one, then lubricate them.
Using the wrenches included in the tool’s repair kit, reassemble the piston mechanism, poppet head, and driver assembly.
Tighten the assembly until the plunger is flush with the poppet’s top.
Test the tool to ensure that it is working properly and that the problem has been resolved.

Replace the trigger valve

A damaged trigger valve is one of the common reasons a nail gun leaks air from the trigger. Replacing it is the only solution to this problem. Here is how to replace the trigger valve;

First, ensure that your nailer is not attached to the air hose.
Then, remove the valve’s retaining pin.
Remove the trigger valve once the valve pin has been removed.
Examine the cylinder from where the valve emerged to ensure that no small pieces of debris are left behind.
Remove the cap from the new valve body and apply a light coat of the provided grease to all of the O-rings on the assembly.
Gently insert the valve into the bore, keeping it square to the valve body to avoid tearing the O-rings.
Start the retention pin back into its hole, making sure the groove in the valve body lines up with it, then gently tap it back into place with the roll pin.
Finally, hold the trigger in place, align the holes, and gently tap it in place with the roll pin.

Why is my nail gun leaking air from the exhaust?

Your nail gun is leaking air from the exhaust because the O-ring is not sealing correctly or the pistol ring is damaged.

O-ring not properly sealed

If you have an air leak from the exhaust vent or the rear exhaust port, the most typical cause is that the O-rings around the seal at the top of the cylinder are not sealing properly and are allowing air to pass through. If the “O-Ring” fails to seal, air will escape and cause a leak. While this may appear to be a difficult repair, don’t throw away your tool just yet; the fixing may be simpler than you think.

You can follow our guide below on how to fix this issue.

Damaged pistol ring

Another common reason your nail gun is leaking air from the exhaust is a damaged pistol ring. The piston ring is essential for sealing the piston to the cylinder. This pressure propels the piston down the cylinder when the gun is discharged. The piston ring will wear out and the seal will be lost over time. This will cause air to leak from the exhaust of your nail gun.

A damaged piston ring must be replaced because it allows air to escape, resulting in a poor drive on the nail. Below in this article is a simple step you can follow to replace it.

How to fix a nail gun that is leaking air from the exhaust?

You can fix a nail gun that is leaking air from the exhaust by replacing the pistol ring or lubricating the O-ring.

Replace the pistol ring

When the pistol ring in a nail gun is damaged, it will cause the nail gun to start leaking air from the exhaust. When this happens, it’s essential that you replace the pistol ring. Here is how to replace the pistol ring;

Remove the nail gun’s top cap.
Remove the nail gun’s piston.
Remove the piston ring from the piston.
Install the new piston ring on top of the piston.
Apply a little layer of lubricant or Vaseline to the piston ring.
Work the piston ring into place with care (without cracking it).
Replace the assembly in the gun. (Note the grooves in the driver. Those grooves must return to the rear of the pistol.)
Place the piston in the cylinder (aligning the driver).
Attach the gasket on the gun’s top.
Fit the head valve.
Tighten the screws used to line the head valve with the gasket.

Lubricate the O-ring

If the “O-Ring” fails to seal, air will escape, causing a leak in the exhaust. The fix for this problem is very simple. All you have to do is lubricate the O-ring. Here is how to do it;

Ensure the air tool is off
Stretch the “O-Ring” on the firing valve
Apply lube

Note: Do not lubricate the tool’s magazine because this will attract dust and debris.

Why is my nail gun leaking air from the top?

The reason your nail gun is leaking air from the top is because of a leaky seal. A failed gasket or a broken collar is another reason your nail gun leaks air from the top.

Leaky seal

If you hear air leaking from the top of your nail gun, it could be because the seal inside the nail gun is broken. The seal helps ensure that there is no air leakage between the piston and the cylinder. However, over time, it may wear down and crack, requiring you to replace it to keep the engine running at its best. In this post, you can check our simple DIY steps on how to replace it below.

Failed gasket

Gaskets are used to provide a seal between two joining pieces. If air leaks between the top piece and the housing, the gasket has failed. If the gasket in your nail gun fails, you need to replace it immediately to avoid further problems with your nail gun. Below in this post, we will walk you through simple steps on how to replace it.

Broken collar

A broken collar is one of the common reasons air leaks from the top of your nail gun. The collar serves as a seal and a spacing collar for the nail guns. This is a neoprene part that is prone to deterioration over time.

If you’re experiencing an air leak in your nail gun, check the collar. If you notice it’s broken, then you need to replace it. Below is a simple guide on how to replace a collar.

How to fix a nail gun that is leaking air from the top?

You can fix a nail gun that is leaking air from the top by replacing the seal. Replacing the gasket or replacing the collar is another way to fix a nail gun leaking air from the top.

Replace seal

A damaged seal will cause air leakage in your nail gun from the top. It’s essential to replace the seal to get your nail gun to start working effectively. Here is how to replace it;

Remove the top cap.
Remove the seal and examine it for wear and damage.
Replace the seal and install a new gasket between the nail gun housing and the top cap. For a proper seal, gaskets should only be used once.
Reattach the top cap and tighten the screws in an alternating pattern, a little at a time, to seat the gasket and keep it from leaking air.

Replace gasket

If air leaks between the top part of your nail gun and the housing, the gasket has failed. Replacing the gasket is the only solution to this. Here is how to replace it;

To change the gasket, remove the top piece and throw away the old one.
Clean the two mating surfaces and place the new gasket.
To seal the gasket, tighten the screws in an alternate pattern a bit at a time.

Replace collar

The collar is an essential part of a nail gun, and once this part becomes damaged, it’s vital that you replace it. If you don’t, air will keep leaking from the top, affecting your nail gun’s efficiency. Here is how to replace it;

Remove four Allen screws from the gun’s top cap.
Gently take off the old collar
.
Install the new collar.
Reinstall the top and tighten the screws.

Why is my Porter Cable nail gun leaking air from the trigger?

The reason your Porter Cable nail gun is leaking air from the trigger is because the pistol head valve is damaged. The piston head valve regulates air flow into the cylinder chamber, causing the piston/driver assembly to strike the next nail. If you hear air seeping from the trigger of your Porter Cable nail gun, it could be due to a faulty piston head valve.

You need to inspect the head valve for any damage. Here is how to inspect it;

Remove the top cap from your Portal Cable nail gun to check the piston head valve.
Pull the piston head valve from the cap using a pick.
Examine the piston head valve for evidence of wear or damage, such as worn-out O rings, cracks in the piston head valve, or anything unusual.

If you notice any damage, then you need to install a new head valve.

Why is my Hitachi nail gun leaking air from the trigger?

The reason your Hitachi nail gun is leaking air from the trigger is because of the trigger valve in your Hitachi nail gun is bad. The trigger valve regulates the flow of compressed air, which in turn regulates the driver assembly. When the trigger is pressed, the air is released, forcing the driver assembly down. If your Hitachi trigger valve becomes bad, it will leak air. When this occurs, you need to replace it.

Here is how to replace the trigger valve;

Remove the magazine.
Remove the grommet on the side of the trigger and pull out the pin or pins.
Remove the trigger valve with a wrench.
Clean the inside and apply a small amount of Vaseline on the O rings.
install the new trigger valve
Put everything back together.
Put the magazine back on.