How to Change Fork Seals on a Harley Davidson

Maintaining your bike is essential for a smooth and enjoyable ride. Unfortunately, many riders overlook the importance of regular checks and maintenance, particularly when it comes to crucial components like fork seals. These seals play a vital role in preventing oil leaks, but over time, wear and tear can cause them to deteriorate.

If the idea of replacing fork seals seems intimidating, fear not. With a little guidance, you can quickly learn how to change fork seals on your Harley Davidson and keep your bike in top condition.

Signs That Your Fork Seals Need Replacement

Recognizing the warning signs of weakening fork seals is crucial. Over time, you may notice increased play between the stanchion and the leg, indicating a need for replacement. It’s important to replace both the seals and the bushes, as they are integral parts of the seal.

A clear indication that your fork seals need changing is a noticeable oil leak. When the seals fail, you’ll observe a significant amount of oil leakage.

Step-by-Step Guide: How to Change Fork Seals on a Harley Davidson

Before diving into the process of replacing your fork seals, take a few necessary steps:

  1. Create a Designated Workspace: Prepare a dedicated workspace where you can clean the fork seals and other parts. Engine oils can stain furniture and materials, so it’s crucial to have a suitable area for the task.
  2. Replace One Seal at a Time: To minimize risk and ensure a smooth process, replace one fork seal at a time. Avoid opening both seals simultaneously to prevent complications.
  3. Treat Each Fork Independently: Remember that both fork seals wear out differently. Therefore, it’s essential not to mix them up during the replacement process. Work on one fork seal, complete the replacement, and then proceed to the next.

Now, let’s delve into the process of replacing the fork seals:

  1. Loosen the Sealing Knobs: Before safely jacking up your bike, ensure you loosen the sealing knobs located near the handlebars. This step allows you to lift your bike securely.
  2. Remove the Calipers: Once your bike is properly jacked up, remove the calipers, mudguard, and wheel. This provides easier access to the seals while avoiding any damage to these components. Secure the brake calipers with a length of cable, as you won’t be operating the hydraulic system during this process. Remember not to engage the brake levers after removing the calipers.

By following these steps, you can successfully change the fork seals on your Harley Davidson, ensuring optimal performance and preventing oil leaks. Don’t forget to prioritize regular maintenance and inspection to keep your bike in prime condition for years to come.


When it comes to motorcycle maintenance, extracting all the oil from the fork tubes can be a challenging task. Follow these instructions to perform this crucial step effectively:

  1. Remove the Seals: Using a six-millimeter hex socket, carefully detach the seals. This ensures proper access to the fork tubes for subsequent steps.
  2. Drain the Oil: Once you have safely removed the tubes, it’s time to drain the oil. To do this, use a container or bowl specifically designated for oil disposal. Remember to work on one fork at a time to maintain clarity and avoid confusion.
  3. Expedite the Oil Removal: For quicker oil drainage, gently compress and extend the fork a few times. However, exercise caution and avoid excessive force to prevent any potential damage.
  4. Document the Positioning: To facilitate reassembly, take meticulous notes on the positioning of each item. This record will be invaluable when it comes time to reinsert the components correctly, ensuring a seamless restoration process.

By following these comprehensive steps, you can successfully extract oil from the fork tubes while maintaining the integrity of your motorcycle. Remember to exercise patience and precision throughout the process.


The following steps must be taken in order to remove the bike’s fork tubes:

  1. The nuts holding them in place should be removed. They may be found next to the bike’s grip.
  2. In order to release the triple-tree clamp bolts, get your torque wrench.
    Holding each tube in place will help you loosen the triple-tree bolt. The tubes are fixed in place by these bolts. Your tubes may fall to the ground after they are turned off.


The tubes should be put on a table. You must do the following in order to remove the tube’s seal:

  1. With the use of a flat-head screwdriver, remove the cap from the bottom legs. Put the screwdriver on the cap and strike it briskly. By doing this, you can remove the cap more easily.
  2. The seals are now hidden under these coverings. Repeat the procedure with the seals after removing the caps. You’re going to replace the seals, so don’t worry about breaking them.
  3. Make sure you take out everything that is in the tubes. These include the snap ring that has to be taken off and the bottom plunger assembly. The ring may be taken off with a straight-head screwdriver.


You have been waiting for this. You can now remove the damaged fork seal after finishing all the other stages.

  1. Securely grasp the slider. After that, to release the seal from the slider, smoothly jerk the fork tube many times.
  2. Keep in mind that if the fork has a guiding bushing, the seal will only come out of the slider. Other bikes might not have one, but the Harley does.
  3. You should consult your bike’s handbook before further removing the fork to look for damage.
  4. Keep in mind that changing a number of components, including the sliding bushings and O-rings, necessitates entirely removing the fork.
  5. Start putting the fork back together once you’ve cleaned it and removed the old seals. Look through your notes.
    Publish the
  6. At the end of each slider, secure the screws holding the damping rods in place with fresh copper washers.


  1. Apply a tiny quantity of lubricant to the exterior of the seal before installing the new one. As a result, it will be simpler to insert the new component into the slider.
  2. To avoid any damage when you reinstall the fork, add extra oil to the sealing groove.
  3. Use a fork seal driver to put the replacement seal in place. If you don’t have one, there is nothing to be concerned about. A pipe can also be used.
  4. Drive the seal in with a tap. Before you begin tapping, be sure to use the old seal as an underlay. To force the new seal in, don’t touch too firmly. Do not use any sharp items under any circumstances.
  5. You should be able to reinstall the circlip into its groove once the seal has been sufficiently pressed into the slider. Don’t forget to include all the parts you took out of the old seals.


You’ve almost completed changing your fork seals. Now all you have to do is pour fork oil into your fork tube. Either at work or immediately into the bike, you may fill the tube. Follow your comfort level. Personally, I enjoy adding fork oil to the motorcycle.
Always use the proper viscosity oil for your particular bike. Put exactly the amount of oil that is required for your fork tube. Check the fork tube’s oil need in your bike maintenance manual. Typically, a Harley needs 300 millilitres or 10.2 ounces of fork oil.


You may now lower your bike from the jack after carefully reassembling all the pieces. Do a test ride to verify whether the fork seals are oil leaking once more.
Consult the service handbook for your bike if you don’t know where to find any of these components. It is the finest source you have for understanding the location and operation of every part of your bike.

Why Do Fork Seals Crack Over Time?

You should probably replace your fork seals if you ever notice oil seeping from them. Because of friction and rust on the stanchion, the fork’s slider or tube, fork seals become damaged. There is a lot of friction between the seals since the tube is continually rising and falling.

Additionally, even the smallest flaw might break the seal, allowing the oil to flow. One of the most frequent causes of fork seal damage is this. Like the rest of your bike, your forks seals need to be maintained. Avoid using seal cleaning products that slip beneath each ring. As a result, grit and grime are forced into the fork’s body, severely harming the fork seals.


How long ought fork seals to endure?


This depends on how frequently and where you ride your bike. For instance, your fork seals may stop working a few years after you buy them if you drive on roads with plenty of potholes or across dusty terrain. Fork seals can also be harmed by prolonged inactivity with the bike. Be aware that the lifespan of your engine oil is finite. Oil should be changed at least twice every two years.

Keep in mind that repairing your fork seals every two years is the best approach to maintain their condition. You are capable of handling things on your own.


Is the quantity of oil leaking from your bike significant? Perhaps it’s time to buy fresh fork seals. On a Harley, or any bike for that matter, replacing the fork seals is definitely not simple. Because of this, the majority of individuals don’t even attempt this task. However, if you keep putting off doing this, you run the danger of hurting your hog.

Are your fork tubes in need of more assistance? Know what your bike requires before contacting the nearby bike shop.

FAQ: Maintaining Your Harley Davidson’s Fork Seals – A Comprehensive Guide

Q1: What are the signs that my fork seals need replacement? A: Signs of weakening fork seals include increased play between the stanchion and the leg and noticeable oil leakage.

Q2: Can I replace both fork seals at the same time? A: It’s recommended to replace one fork seal at a time to minimize risks and complications.

Q3: Should I treat each fork independently during the replacement process? A: Yes, because both fork seals wear out differently, it’s essential not to mix them up during the replacement process. Work on one fork seal at a time.

Q4: How do I drain out the oil from the fork tubes? A: To drain the oil, remove the seals using a six-millimeter hex socket, and use a designated container for oil disposal. Gently compress and extend the fork for quicker drainage, and document the positioning of components for reassembly.

Q5: How do I remove the fork tube from the bike? A: You should remove the nuts holding the tubes, release the triple-tree clamp bolts using a torque wrench, and loosen the triple-tree bolt to remove the tubes.

Q6: How do I remove the caps from the seals? A: To remove the caps, use a flat-head screwdriver and strike it briskly. The seals are located under these caps.

Q7: How can I remove the seals? A: Securely grasp the slider and jerk the fork tube to release the seal. If your fork has guiding bushings, the seal will come out of the slider. Make sure to consult your bike’s manual for specific instructions.

Q8: How do I install the new seals? A: Apply lubricant to the exterior of the new seal and add extra oil to the sealing groove. Use a fork seal driver or a pipe to gently tap the seal into place. Reinstall the circlip and all other removed components.

Q9: How do I fill the seals with fork oil? A: Fill the fork tube with the recommended viscosity fork oil, following your bike’s maintenance manual for the correct amount. You can either fill it at work or directly on the bike.

Q10: Why do fork seals crack over time? A: Fork seals can crack due to friction and rust on the stanchion, tube, or slider. Even the smallest flaw can break the seal and cause oil leakage.

Q11: How long should fork seals last? A: The lifespan of fork seals depends on factors like riding conditions and maintenance. Frequent pothole-ridden roads or dusty terrains can shorten their lifespan. It’s advisable to replace fork seals every two years to maintain their condition.

Q12: Is replacing fork seals on a Harley Davidson a difficult task? A: While it may seem challenging, with the right guidance and tools, you can successfully replace fork seals on your Harley Davidson. Regular maintenance is essential to keep your bike in prime condition.

Q13: How can I assess if my bike needs fork seal replacement? A: If you notice a significant amount of oil leakage from your bike, it’s time to consider replacing the fork seals. Delaying this maintenance can risk damage to your motorcycle.

Q14: How often should I change my engine oil for optimal fork seal performance? A: Engine oil should be changed at least twice every two years to maintain your fork seals’ condition.

Q15: Do I need any special tools for changing fork seals on a Harley Davidson? A: While specialized tools like a fork seal driver can be helpful, you can also use alternative methods, like a pipe, for certain tasks.

Q16: Can I replace fork seals on my own, or should I consult a professional? A: You can replace fork seals on your own if you have the necessary tools and follow the step-by-step guide carefully. However, if you’re uncertain or uncomfortable, it’s always a good idea to consult a professional or a reputable motorcycle mechanic.

Q17: Where can I find detailed instructions on changing fork seals for my specific Harley Davidson model? A: Your bike’s service manual is the best source for specific instructions and guidance on changing fork seals for your particular Harley Davidson model.

Q18: How can I determine the correct fork oil viscosity and amount for my Harley Davidson? A: Refer to your Harley Davidson’s maintenance manual to find the recommended fork oil viscosity and the correct amount for your fork tubes.

Q19: What should I do if my fork seals are leaking again after replacement? A: If you experience oil leakage after replacing the fork seals, consult your service manual to ensure that all components have been reassembled correctly. If the problem persists, consider seeking professional assistance.

Q20: How can I maintain the integrity of my motorcycle’s fork seals in the long run? A: Regular maintenance, including timely fork seal replacement, is crucial for preserving the integrity of your motorcycle’s fork seals. Additionally, avoid using seal cleaning products that can push grit and grime into the fork’s body, which can harm the seals.

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