What Are Fork Bleeders and Why You Need Them?

Fork bleeders are used to release the excessive air pressure inside the dirt bike front forks. Factory fork bleeders need a screw driver and are difficult to reach and take time to bleed.

One of the things many riders seem to neglect is to bleed the excessive air build-up inside the front forks. This air build-up can quickly affect the suspension performance as it slows down the front forks and can make the suspension feel rigid, harsh and/or slow.

Fork bleeders are a game changer for quickly neutralizing excessive air pressure build-up inside the front forks. Fork bleeders are small hollow spring loaded air screws that replace the factory front fork air screws on top of the front fork caps. They enable a push button style quick release of the excessive air buildup inside the front forks.

In this article we will explain:

  • What are the benefits of using quick air release fork bleeders
  • How do the quick air bleeders or fork bleeders work
  • How to install quick release fork bleeders

Let’s get started!

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Dirt bike front fork and the fork cap with fork bleeders installed
A quick release fork bleeder installed on a fork leg. With a push of a button, the excessive air is released inside the fork leg.

Front Fork Air Reservoir in a Nutshell

Front fork suspension components work in parallel with the fork oil moving around inside the fork leg and the air chamber reservoir. The air inside the fork leg is an important suspension element and needs to be neutralized with fork bleeders.

When you ride and even when the dirt bike is stationary, the amount of air pressure inside the front forks is changing for various reasons.

Front fork designs are typically open chambered or closed chambered, and the main difference in these designs is the air reservoir design. The open chambered forks have zero pressure air reservoir whereas the closed chambered forks have an adjustable high pressure chamber pushing against the oil.

Temperature Affects Air Pressure Inside Forks

The air inside the fork is temperature sensitive. Air expands in hotter environments and contracts in colder temperatures. These changes related to the ambient temperature affect the air pressure inside the fork, therefore needing to be reset by opening the fork bleeders.

While riding, the suspension oil and internal components will also heat up. This heat dissipates also into the air, thus further expanding the air and adding more back pressure.

Small leaks, dirt, and debris in the dust and oil seals also typically add air inside the fork legs, usually during the compression cycle pushing some air inside the forks. This also adds to the overall air pressure build-up in open chambered forks.

The only way to reset the suspension performance, is to release or neutralize the internal air pressure inside the fork legs using fork bleeders. This is done by opening the small screw on top of the fork leg cap. Now, installing quick release air pressure relief valves or quick release fork bleeders makes the process much quicker and easier.

How Air Pressure Affects Suspension Performance

The air inside the fork leg works parallel with the fork oil.

The open chamber fork design has typically about 4 inches of air on top of the oil level and the fork cap. When the fork compresses, the air is also compressed inside the fork. This air pressure affects the compression and rebounding speed of the fork leg.

Being able to reset the air pressure with fork bleeders will help the suspension to work as designed.

Dirt bike front fork leg on the table next to fork bleeders
Fork bleeders can wear out and cause air leaks. Inspect and replace defective quick fork bleeders.

The excessive air inside the forks can usually feel like the plushness is gone and the riding starts to feel harsh. This is usually an indication to bleed the forks for excessive air build-up using fork bleeders.

How To Adjust or Release Front Fork Air Pressure

If your forks are open chambered, the service manual instructs to open the small fork bleeder screws on top of the fork caps.

This should be done prior to every ride day to balance out the amount of air in each fork leg. The small screw has a rubber o-ring seal and can be under quite a lot of pressure, so be careful not to let the screw fly away when opening each of the fork bleeding screws.

When you open the fork air bleeder screw slowly, you should hear the excessive air escaping from the fork leg. After the air pressure is stabilized, tighten the screw back in. You don’t have to fully remove the air screw, since the air is able to escape through the threads with an audible hiss. Using quick release fork bleeders, this happens with a push of a button on top of the bleeder cap.

In a closed air fork designs, you can adjust the air pressure inside the fork leg by using a fork pump. There are no air bleeder screws to worry about. However, the same principles apply. Check the air pressure frequently as it does change based on outside temperature. Refer to your owners manual for detailed instructions.

Fork Bleeders Help Bleed Excessive Air Quickly

Sometimes called as speed bleeders, quick release fork bleeders, or simply fork air quick bleeders will make bleeding the excessive air out of the front forks very easy.

Usually, the speed bleeders work with a push button style quick air release valve that can bleed the forks in seconds.

Front fork leg upright ready for air bleeder installation
Speed fork bleeders replace the original air screw with the o-ring and makes fork bleeding easy.

After installation, you simply press the top of the speed fork bleeder to release any excessive air in open chambered forks to reset the air pressure to the surrounding ambient air pressure. This guarantees normal fork performance and also prevents the forks from fork oil seal leaks.

How To Install Front Fork Bleeders

Installing the fork bleeders is a quick 10-minute task.

Firstly, you will need to buy the quick release fork bleeders, that will fit the thread size and length for your dirt bike.

In our 2018 KTM XCW 300, and its WP Xplor forks, we have M4x0.7mm threads. You can measure the old factory screw size and length to ensure fitment.

We use these Motion Pro fork bleeders (click to check the current price on Amazon.com) and they do seem to hold air well and not leak on our KTM Xplor forks. You can find more quick release fork bleeders here to fit your specific dirt bike.

Step 1. Remove the Factory Air Bleed Screws

To begin the installation of the quick release fork bleeders, you need to remove the factory air bleed screws located on the fork cap. You do not need to remove the fork leg off the dirt bike.

Place the original air release screws aside and store them as spares in case of breakages or issues later on. It is possible to damage or break the quick bleeders, so packing a spare is always a good idea.

Greasing air screw o-ring with grease to ease installation
Apply some grease on the o-ring to prevent damaging the seal when tightening the fork bleeders in place.

Step 2. Install the Quick Release Fork Bleeders

To install the new quick release fork bleeders, you should apply some grease or lube on the o-ring to avoid damaging the seal when tightening. Do not over tighten the bleeders as they have an o-ring for proper seal.

Step 3. Testing Out the Quick Release Air Bleeders

After installation, properly testing the bleeders will take some time. Pumping the front forks up and down should not create any air pressure build up so that would be a waste of time to try. Instead, next time you get ready to ride, push the quick release fork bleeders and listen to the air release. The air usually builds up as the ambient temperature changes and the next morning should be the first chance to test them out.

Once you hit the trails before starting the dirt bike, push the bleeders again to neutralize the pressure inside the forks. Test them again after the first ride.

When To Bleed Air From Front Forks

These are the typical situations when these quick release fork bleeders come in handy and should be used:

  • After strapping the dirt bike down for transportation. Strapping the front down increases the fork air pressure and can cause oil seals to leak during transportation.
  • After transportation. Once you release the front forks, reset the air pressure inside the forks.
  • Elevation changes can cause low or high pressure difference inside the fork. Bleed often when riding at high elevation changes.
  • Temperature changes. Bleed before you ride.

Fork Bleeders Can Help Prevent Leaky Forks

Releasing the excessive air build-up inside the forks is a great way to prolong the oil seal life in the front forks. The excessive air pressure can push out the oil and quickly cause new oil leaks. This usually happens when there is already some dirt inside the dust seal and it’s traveling under the oil seals. Releasing the excessive air build up regularly is easier with quick release fork bleeders and you should use them often.

Cleaning the fork oil seals with a seal bullet or similar tool will help and usually stop minor dirt related leaks. If the leaks quickly come back, inspect and replace the fork oil seals during the next oil maintenance cycle.

Make sure to check out our complete instructions for how to change fork oil on open chambered forks. It also covers how to change the oil seals.


Fork bleeders are a must for any open chambered forks. The quick air release will help prevent fork oil leaks and keep the forks running at optimal performance levels.

Fork bleeders are simple to install and easy to use and are likely one of the best small upgrades every rider should install on their dirt bike.

Keep airing out those forks!

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