Replace Fork Seals Without Disassembly? The 135 Top Answers

The moment you see even the tiniest trace of fork oil on your fork slider, your heart sinks. You know it’s only a matter of time before a gusher springs out of your fork seal. This causes your suspension to spin in a pogo stick with no dampening. It’s neither fast nor safe. To add salt to the wound, the fork oil will inevitably soak your front brake pads. Now you have another safety issue and you need to add new brake pads to the suspension bill at the dealer. Basically, something as simple as a leaking fork seal can ruin a day of riding or racing.

Fork seals leak from normal wear and tear, age and dirt getting into the seals. Imperfections and nicks in the chrome can also cause your fork seals to leak. However, most of the time when your fork seals are leaking, it is simply because dirt is getting caught in the seal holding it open and allowing fork oil to sneak past.

When you first notice the leak is the best time to take immediate action. While you might be tempted to ignore it for now so you can keep racing, you know what will happen if you ignore it. If you’re pulling your hair out wondering why your fork seals keep leaking, read on to uncover the problems and fix them so you can get back racing fast.

How do fork seals work?

A modern motorcycle suspension is simply amazing. The travel they have and the internal components that control the rate of compression and rebound are all the result of over 100 years of evolution in motorcycle design.

One reason today’s suspension is so good is the use of oil as the rate controlling medium in the suspension. The challenge, however, is keeping the oil where it belongs while allowing the suspension to cycle up and down thousands upon thousands of times. The only component that holds the oil, even under high pressure, during rapid compression is a tiny rubber “lip” called the oil seal.

To cut a long story short, this tiny “lip” sits between the inner and outer fork tubes. As you can imagine, the connection between the fork inner tube and the oil seal must be perfect so that the oil does not leak. When the oil seal gets old or hard, it no longer prevents the oil from leaking out. If something gets stuck between the seal and the fork tube as described above, oil can leak out.

First, what to look for

As mentioned above, watch out for oil dripping off the fork seal. Sometimes the oil is hard to see, but don’t worry, the oil will attract dirt and soon you’ll see a dirty mess around your fork seal (conventional forks) or at the bottom of your fork tube near your front axle (upside down). forks like on modern motocross bikes). Basically, oil dripping down the front shaft should be your first clue that your fork seals are leaking.

Another obvious clue is when there is a puddle of oil under your fork, or your suspension just feels like an uncontrolled and springy spring. If enough oil comes out, your bike will become unsafe.

What makes seals leak anyway?

Seals leak through normal wear and tear

Seals are put under a lot of stress with normal use, and even more if they are ridden harder than normal. When racing dirt bikes or riding off-road dirt trails, your seals work even better to keep dirt and other debris out. Because they have a hard life, you should service your fork oil seals or change your oil seals after 40 hours of riding. Most people just wait for them to leak to service or replace them, but serious racers should be prepared and never let a leaking fork seal ruin a race day or their racing results.

Even if you rarely ride your bike, you should change the oil and seals every two years because idle time dries out your fork seals and causes leaks.

Dirt and other deposits can get into the seals

As previously mentioned, dirt, grit, and other debris get between the seal and the inner fork tube, creating an incomplete seal. If so, you need to clean them up according to the methods detailed in the next section.

Imperfections in the fork inner tube can cause leaks

When riding, stones and other foreign objects inevitably fly up and dent the hose or cause scratches or chips on the fork. When this happens, it will cause your seals to leak before they wear out. You’ll need to check the fork from time to time to make sure this doesn’t happen.

If this is the case you can use 400 grit sandpaper to buff them, a side to side motion rather than an up and down motion is better, but a “cross hatch” pattern similar to honing is best a cylinder. If your fork tube was faulty, chances are the fork seal was damaged as well.

You may need to fix the imperfection and replace your fork seal to completely fix the leak. If you only replace the fork seal, the imperfection in the fork tube will simply damage the new fork seal as well.

Note, however, that not all chips or dents can be 100% polished out. If this is happening to your bike, you should consider re-chroming it. Suspension companies like SGB Racing can recoat your fork tube and even apply a higher performance coating to improve your suspension function.

Extended pressure by lashing straps

There’s enough stress on those bad fork seals already, and then when you use a mounting system that compresses the front forks in transit, you’re putting a constant source of stress on the fork seals. Check out Risk Racing Lock and Load Systems, they will undoubtedly extend the life of your fork seals, apart from making your life easier when transporting your bikes.

What can you do to repair fork seals?

Aside from replacing the seals, there are several things you can do to get your fork seals fixed and racing again before you know it. If you can’t do it yourself, consider taking your bike to a qualified bicycle mechanic who will do it for you. Replacing fork seals can cost anywhere from $100-$200 depending on how many parts need to be replaced.

Lift the dust cover and clean underneath

If you know what you’re doing, gently pry the dust seal apart with a flathead screwdriver, being careful not to scratch the fork or damage the seal. Use a lint-free cloth or cotton swab to remove any mud or dirt stuck under the lip before putting everything back together.

If that doesn’t fix the problem, remove the dust seal and wrap a piece of camera film or another flexible, thin object around the shaft, then push it up until you get under the lip. This method can remove any residue that a cotton swab might miss. Then reset everything.

The disadvantage of this method is that the debris that caused the leak is pushed into the suspension. The small valve in the suspension can’t handle dirt and therefore more damage can be caused if a simple leak is fixed in this way.

Use the Seal Doctor on the fork

Leaks occur almost everywhere at the worst times, e.g. B. when you are on the track or hitting the trails. Having the right tools to quickly fix a leaking fork seal can save the day. Risk Racing’s TheSeal Doctor is just the tool you need. This product received 5 stars out of 5 from all the top motocross magazines, proving that it is the best tool to fix leaking fork seals.

Just lower your dust seal and put the Seal Doctor on your fork tube, pop the tooth into the leaking seal and twist. The Seal Doctor’s design maintains the correct position and angle as you rotate around your fork tube. It effortlessly pulls the dirt out of the fork rather than pushing it deeper into the fork. The bottom of the Seal Doctor has a second tooth design to clean your dust seal.

The Seal Doctor also comes with a protective holster so it can be safely stored in your toolbox or hiking backpack so you always have the right tools for the job. There are other products on the market that attempt to do the same thing as the patented Seal Doctor, but none do it quite as well.

Replace fork seals

Fork seals should be replaced after 40 hours of riding, or two years if you don’t ride very often. Even if you clean the gaskets regularly, they will eventually wear out and leak no matter what you do to ensure a tight seal. If you don’t know how to do it, you might want to take it to your local bike mechanic or befriend a mechanically inclined moto buddy and learn exactly.

You need special tools such as B. Fork seal driver to do the job by yourself. These tools can be expensive and specific to your bike or suspension size. A trip to the dealer to fix this problem is also expensive. The cheapest and quickest way would be to start with the Risk Racing Seal Doctor.

Why do fork seals keep leaking?

They’ve done everything they can to fix the fork seals, but they’re still leaking. This can be very frustrating, but for your own safety, it’s important that you get it repaired properly.

The fork seals are not properly reassembled

If the fork seal is leaking immediately after replacing it with a new fork seal, the problem is likely due to improper installation of the new fork seal. The sharp edges on the fork tube can often cut through the sensitive seal during installation. An experienced mechanic will know the proper secrets for installing the fork seal over the sharp edges of the fork tube to avoid damaging the new fork seal.

Fork seals are not fully cleaned

If this doesn’t stop the leak, you might want to recheck the seals as they may not be completely clean. Even a small speck of dirt can cause the oil to leak out. Repeat the cleaning process until you are sure you have removed everything under the gaskets.

Once you’ve cleaned the seals, wipe all the dirt and bugs off the fork after each ride.

There are nicks in the chrome under the seal

Rocks and other debris can fly up and nick the chrome under the gasket, creating small dents that allow small amounts of oil to leak out. The best way to take care of this is to take a super fine piece of sandpaper to buff out the dents or nicks. However, some scratches may not be polished out. In this case you may need to re-chrome the fork tube.

Transport your bike differently

If you keep getting fork seal leaks after repair or replacement, consider how you will transport the bike and avoid using tie-down straps to transport your bike. The Lock-N-LoaderLock-N-Load Pro Moto Cargo Systems are the best way to transport your bike while reducing stress on your fork seals.

Consider the conditions you ride in or install additional protection

If you ride in sandy or muddy conditions, you are more prone to fork seal contamination. You can fit special neoprene fork seal covers to further protect contaminants from reaching your fork seals.

Conclusion

Fork seals are delicate things and require frequent maintenance to prevent leaks. If you follow the suggestions in this article and your fork seals are still leaking, you may need to replace the fork tube. But until you decide, take it to your bike mechanic for him or her to look at to find the cause of the leak.

Remember that the Seal Doctor device is the best tool on the market for servicing or repairing fork seal leaks. It removes the dirt from the fork to make the process quick and easy. They come in multiple sizes and work for all bikes, dirt and street.

Keeping your fork seals in tip-top shape means you can race the same bike for years to come.

This article was co-authored by wikiHow staff. Our trained team of editors and researchers validate articles for accuracy and completeness. wikiHow’s content management team carefully oversees our editorial team’s work to ensure that every article is backed by trusted research and meets our high quality standards. This article has been viewed 259,838 times.

Article overview

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To replace the fork seals, first unscrew the 2 bolts that attach the fork legs to the frame and the fork leg caps. Next, loosen the caliper bolts and front axle before inserting the bike and locking the rear wheel. Then lift the front wheel and remove the calipers, fender, front wheel and other hanging cables. Disassemble the fork and remove the old fork seal. To prepare the fork for the new seal, rub away rust and imperfections with an oil-soaked cloth. Then place the new gasket over the upper tube and tap the gasket down with a gasket driver. Reassemble the fork by replacing the damping rod in the fork and reinstalling the clip and dust seal on the fork. Pour new oil into the fork, reinstall the spring, screw on the fork cap and tighten the bolts. Repeat the disassembly and assembly of the fork on the second fork leg. Then reassemble the front end of your motorcycle and hit the road! See below for more detailed information on replacing fork oil seals.

If you notice oil leaking from the fork tube of your motorcycle or dirt bike, it may be time to replace the fork seals. Bad fork seals can also affect your bike’s performance and handling, so get it taken care of as soon as possible.

Replacing your fork seals can cost anywhere from $50 to $500 depending on whether you do the job yourself or take it to a mechanic. The parts aren’t very expensive, so most of the cost will depend on how much you’re paying for the labor.

Replacing your fork seals can cost anywhere from $50 to several hundred dollars depending on who is doing the job. If you take your motorcycle or dirt bike to a local garage, expect to pay anywhere from $120 to $175.

You may find that the cost is much higher if you take it to a dealer or certain bike shops that charge more for the job.

Estimate for replacing fork seals

Value Garage $100-$135 Moderate Garage/Chain Repair Shop $125-$160 Dealer/Bike Shop $175-$500 Home Improvement $45-$150

The good news is that replacing the gaskets is a fairly easy task and many owners choose to do the job themselves. If you’re interested in taking the do-it-yourself approach, you could end up saving a ton of money on labor costs.

Cost of replacing fork seals yourself

If you decide to replace your fork seals yourself, you will pay a lot less than taking it to a workshop or dealer.

You only have to worry about the cost of parts, and any special tools you may need aren’t strictly necessary (but they make the job easier).

The price of the seals themselves depends on what type of bike you have and whether you are buying OEM (factory) or aftermarket parts.

A set of new seals can be as cheap as about $10, or they can be in the $40-$50 range. Most cost between $20 and $30 if you order them from an online retailer.

Here’s what you need to replace your fork seals Fork seals (2)

dust seals (2)

Fork oil (2 liters)

Fork seal driver (optional but recommended)

Fork spring compressor (optional but recommended)

DIY fork seal replacement cost

Total parts cost (without tools) $35-$75 Total parts cost (with tools) $100-200

The time investment in this project mainly depends on how familiar you are with working on the bike and whether you use the tools to make the job easier. Most people spend between two and six hours changing their fork seals.

What is a fork seal?

Fork seals usually refer to the seal kits in the fork of your motorcycle, dirt bike, or bicycle. The fork seals inside the fork are designed to keep the oil inside.

The visible seals on the fork are dust seals and are designed to keep dirt, dust and debris out of the fork. Most people replace all the seals at the same time.

If your fork seal fails, there’s a good chance the dust seal didn’t do its job.

One of the main reasons for seal failure is that dust and dirt particles enter the fork, creating an incomplete seal and allowing oil to leak out.

When to Replace Your Fork Seals

If you observe a leak from the fork seals, it means they need to be changed immediately. You can also change the seals as a precaution. It is recommended that the fork seals be serviced or replaced after 40 hours of riding.

Most owners wait until there is a problem with the fork seals, but by being proactive in addressing this issue, you can avoid dangerous situations.

If you’re using your bike for racing, it’s even more important that you keep up with this type of maintenance.

If you don’t drive often, you should change your seals at least every two years. So if you don’t reach the 40 hour mark within two years, change the seals anyway.

If your bike sits idle for too long, the seals can eventually dry out and crack, causing leaks.

Signs and symptoms of a bad fork seal

The most obvious sign of a leaking fork seal is when you notice oil leaking from the area. Even if you don’t see the oil right away, you’ll likely see a buildup of dirt and grime as the oil mixes from dirt and dust making contact.

You may also notice a small puddle of oil under the fork of your bike while it is parked. Leaking too much oil and getting the oil level too low can cause your suspension to behave differently.

Many riders feel these small changes in their bike’s handling and then look for the oil leak.

Leaking too much oil can create a dangerous situation, so it’s important to be aware of this issue and never ride with a blown fork seal.

Causes of fork seal damage

Motorcycles and dirt bikes put a lot of strain on your fork seals due to the way the vehicle is built.

If you ride your bike harder than the average commuter, e.g. B. if you ride your bike off-road or participate in races, you can put additional stress on the fork seal.

One of the big challenges associated with the fork and seals is keeping dirt and debris out. Driving off-road or on unpaved roads and trails can exacerbate the problem and wear out the seals even faster.

In addition to general wear and tear, dirt, dust, sand, and other debris can get into the fork tube.

If dirt particles get between the gasket and the pipe itself, the gasket will no longer be a tight fit in the pipe, resulting in a weak seal and leaks.

Servicing your fork seals

Keeping your fork seal clean and tidy will prolong part life and keep your bike performing at peak performance.

In addition to regularly rinsing dirt and debris off the machine, you should also periodically inspect your forks and clean the seals.

The best way to save some money on potential repair costs is to perform preventive maintenance to prevent breakdowns.

To clean your fork seals, you should have the following items available: Alcohol based suspension cleaner

rags or shop towels

flathead screwdriver

Choose

8mm T-handle

suspension grease

Allen key or socket wrench

Overall, you’re only looking at $35 or less for these materials, but the result will be worth it if you’re avoiding damage to your bike.

How to clean your fork seals

Follow these steps to clean and inspect your fork and dust seals:

Remove fork guard. Use an Allen key or socket wrench for this task. Remove the fork seal. Use a flathead screwdriver to gently wiggle the gasket down. If necessary, you can use a pickaxe. Clean the inside of the joint. Clean the inside and around the joint with your alcohol-based cleaner. You can also use compressed air to blow away dust and dirt. Pump the fork. Pump the fork up and down, then spray cleaner to remove any hidden debris. Clean the fork seal. Use your alcohol-based cleaner to gently clean the seal. Lubricate the dust seal. Use a very small amount of lube. Reattach the dust seal. Simply slide the dust seal back into place.

The final result

Replacing your fork seals is a necessary task for the regular, routine maintenance of your bike. If you ride your bike hard, riding it off-road or racing, you may need to check your seals more frequently.

Many people wait until they see a leak to look at their fork seals, but prevention is key to avoiding performance problems.

The good news is that replacing your fork seals is a fairly inexpensive job and many owners do the job themselves. If you buy a set of seals online, you can get them for under $40.

If you take your bike to a shop or workshop you will end up paying quite a bit more. You also need to consider time when deciding whether to do the work yourself.

It can take an inexperienced person several hours to change the seals. So if you’re someone who values ​​your time more than the cost of the work, you might prefer to take the bike to a shop.

Keeping your seals in good condition will help prevent oil leaks and damage, and ensure your suspension is working properly.

Establish a routine to regularly clean and inspect your seals for damage to keep your bike in tip-top shape.

Oil change intervals for motorcycle forks

How often do you change the oil in your motorcycle fork?

Now that motorcycle manufacturers have come to their senses and are returning to coil spring forks, it’s time for some of the old tricks to resurface. In 2019, the CRF250, CRF450, YZ250F, YZ450F, KX250F, KX450, Suzuki RM-Z450, YZ125 and YZ250 will all have metal springs. This helps those consumers lost in a mishmash of air valving and confusion working with his forks. KTM and Husqvarna, which have the best, simplest air forks, are the only brands that stick with air—but they can get away with it because their air forks work (and aren’t confusing to live with).

The MXA wrecking crew does everything in their power to avoid sending our test bikes’ forks to revalve. It’s not that we don’t think the suspension shops can improve the performance of the forks; we just don’t want them. we are stubborn We believe we can find a fork fix without having to spend any hard-earned money. We click the clickers every which way we can, and when it comes down to it, we change the fork oil height. Adjusting fork oil height is the trick every suspension tuner has up their sleeve. It works, it’s free, and you don’t need to disassemble the forks.

It should be noted that if all else fails we have the phone number of our favorite suspension shop on speed dial.

What is the effect of changing the oil height? Adding oil to your forks decreases air volume. Because air is compressible, a smaller air space is harder to compress than a larger air space, resulting in a stiffer fork. Because airspace compression is gradual, the rider will feel the reduction in airspace from mid-stroke to bottoming out. Essentially, adding oil to your forks makes them stiffer from the middle up. The obvious consequence of this is that when you take oil out of your forks, you soften them from mid-stroke onwards. Adding or subtracting oil has negligible impact on the first four inches of travel.

How do you add oil? The easiest way to add oil to a fork is with a graduated syringe with a tip small enough to fit into the bleed screw on the fork cap. Use the measuring scale to draw 10ml of fork oil into the syringe. Noleen sells an affordable syringe for $6.95. Call her at (760) 948-1677. Insert the syringe tip into the vent hole so that it seals well; If it doesn’t, oil will leak out without getting into the fork. Remove the o-ring from the bleed screw and put it back in the hole for a better seal on the syringe. Slowly inject 10ml of oil into the forks. It is important to note that 10cc of oil goes in, 10cc of air must come out. Deflating when adding the oil is difficult. The easiest way is to push the syringe down to inject about 1mL of oil and then pull back on the syringe plunger to allow air bubbles to escape back into the syringe. This back and forth motion is tedious but easier than pulling the forks apart. The whole process can be done with the forks on the bike.

How do you lower the oil level? First you need to remove the forks from the bike. With the fork removed, remove the bleed screw from the fork cap. Invert the forks and place a measuring cup (the syringe with the plunger removed works great) just below the bleed screw hole. Gently squeeze the forks by hand to force the oil out of the fork. Don’t worry about oil spray; it doesn’t want to come out. Once the measuring cup shows you’ve removed 10cc, stop and do the other fork leg.

What can be achieved? Taking out 10ml of oil made the fork feel softer from mid-stroke onwards. It’s the easiest and fastest way to take the stiffness of the standard forks in the middle of the travel. If your forks are too stiff, too harsh, or don’t get full travel on your trail, lowering the oil height will make them feel more supple. Conversely, adding oil makes the fork feel stiffer. More oil works best when a rider has a bottom issue.

Don’t be afraid to experiment. When MXA tests a bike with forks that feel too harsh, we take 10cc of oil from each leg (on WP AER forks, we only remove oil from the non-air side). If they’re still hard, we’ve removed another 10cc. We have removed more than 20cc in some cases – you must use the ground as a guide. Consult your owner’s manual to see what the maximum and minimum oil height is for your forks. Adjusting your oil height is a valid tuning process and best of all it’s free.

Leaking fork seals may seem like a minor problem, but it can lead to further damage to the internals of your fork and even to riding and braking safety. In this guide, we’ll go through every step you need to know to replace oil and dust seals on your bike.

Keeping an eye on leaking fork seals is crucial to maintaining optimal suspension performance. Remember that an improperly working suspension is a safety hazard.

Whether you’re out with friends or out on the track on race day, leaking seals can ruin any riding day, especially if that blown seal is on the brake side. If your forks’ seals are just leaking or barely holding oil, your forks aren’t damping or springing like they should. The oil helps create bottoming resistance, allowing the fork to stay in the stroke it is meant to perform.

Most current generation forks contain a closed cartridge that houses the damping and rebound valve as well as the oil. The outer chamber houses the fork spring plus additional oil. When the main fork seals burn out, the oil in the outer chamber leaks out.

If oil seeps down through the seal and down the lower leg, dirt and debris can adhere to the tube. The initial size of the crack in the seal may be small and somewhat imperceptible, but after dirt gets past the dust wiper, it damages the seal itself, causing the oil to leak out faster.

Not only do you have to disassemble your fork this far for a seal change, but it helps visualize the components inside your fork and where the oil is leaking.

Leaking fork seals that are not fixed can allow dirt to seep through the interior of the fork, likely leading to more damage and potentially costly repairs.

Replacing fork seals can generally be performed in a well-equipped workshop using some standard tools and supplies, as well as some readily available specialty tools.

It is important to note that different suspension manufacturers have different methods of disassembly and reassembly. Therefore, always refer to your owner’s manual for specific instructions for your application. This guide is intended as a general guide and not all steps are the same in all applications.

In this step-by-step guide we replaced the fork seals on a set of used Showa cartridge closed forks on a 2007 Honda CRF 450R. For the purposes of this guide, we’re going to focus on a simple seal replacement to get you back on the track or trail rather than a full outer chamber cleaning and seal replacement.

The first step before beginning any repair is to make sure you have the right tools in your arsenal and a set of new gaskets to install. Attempting to “macgyver” things with the wrong tools can easily lead to more repairs and higher costs for you. Below is a list of the tools we used for this project:

Make sure you have the right tools and a clean workspace before you begin. Special hanging tools are readily available online.

47mm ProX fork seal kit

Torque wrench (recommended by a reputable company for accuracy)

Socket wrench (drive 3/8)

8mm socket or 8mm T-handle wrench

10mm socket or 10mm T-handle wrench

17mm, 19mm, 21mm bushings

17mm open end wrench

5mm allen key

Clevis Wrench

#2 flathead screwdriver

47mm fork seal ball

48mm fork seal driver

Grease seal and O-ring

5W fork fluid (or whatever your manual recommends)

pen and paper

600 grit wet/dry sandpaper

Workbench vise with rubberized jaws

oil pan

Suspension-specific cleaning chemicals (e.g. Maxima Suspension Clean)

Awesome Orange (diluted with water 50/50 mix)

Microfiber towels

**NOTE: Tool sizes may vary by suspension manufacturer.

There are many options when purchasing new seals. OEMs are great but can be overpriced. ProX oil seals and dust seals are made in Japan by the same OE suppliers to meet OEM quality without the price tag. They are available both individually and as sets.

Prepare your new seals before disassembly. Find HERE ProX seals for your bike.

It’s always a good idea to start with having all your tools on a clean workbench or table. Start by putting your bike on a stand and removing your front wheel and then your forks. Be sure to remove the fork guards and caliper (if applicable) before loosening the triple clamps and removing the forks completely.

Remove your front wheel, fork guard and caliper (if on the brake side) before removing the fork from the triple clamps.

Check your rebound clicker settings with a flat head screwdriver and make a note of them. To do this, turn the clicker clockwise and count each noticeable notch until it stops. Once it stops, don’t force it. The number of clicks is your setting. You will need to reset to this after reassembling your fork.

If you don’t know where your clickers are set, it’s a good idea to check and record them so you can reset them when you reassemble them.

Now that the clicker settings have been recorded and the fork(s) have been completely removed from the bike, we can begin replacing the seals.

Place the fork in the vise by clamping it at the axle eyelet.

Using a socket wrench/socket, completely loosen the bottom bolt under the axle eyelet.

Be careful with this step, it can be a bit tricky. Once the bottom bolt is loose you need to compress the fork by pulling the top of the fork towards the axle tab.

With the fork compressed and the damping rod exposed, use the open end of the open-end wrench to slide the damping into the center of the “U” shaped prongs behind the locknut and slowly rebound the fork to lock the tool against the axle while dragging.

You will need an open-end wrench, a socket wrench, and two hands for this step. Place the open end wrench on the jam nut and the socket wrench on the rebound bolt and loosen the rebound bolt. Remove the rebound bolt along with the inner adjuster rod from the damping rod.

Compress the upper tube toward the down tube to remove the crown cap wrench from the damping rod jam nut and release the spring tension.

Remove the fork from the vise, being careful not to spill oil, and reposition the fork in the vise so that the upper fork tube is moderately clamped and the top of the fork is tilted down. It is important to clamp in the middle of the pipe where it is roundest and has no taper. Here the lower triple clamp holds the fork.

Use your flathead screwdriver to separate the dust seal from the upper tube. Then, also using the flat head, remove the inner seal clip from the groove in the upper yoke.

Use the flat head to separate the dust seal from the upper tube and remove the seal clip (second photo). With these parts removed from the tube, grasp the lower tube with one hand and the upper tube with the other. Slide the lower tube into the upper tube, then quickly pull the lower tube away from the upper tube with enough force to separate the two tubes, leaving the oil and dust seal on the lower tube.

Remove the slide bushing, pilot bushing, washer, oil seal, seal clamp and dust seal from the top of the down tube and place them on the workbench in the order they were removed. It is also very important to note how the oil seal was positioned. Incorrect positioning will not seal the oil.

Clean your down tube with a clean microfiber and inspect the tube for dents and sharp burrs that may have caused the seal to leak. If nicks and burrs are found, use the 600 grit wet/dry sandpaper lubricated with the cleaning slurry to remove any sharp edges. Wipe the tube with a clean microfiber cloth to remove any contaminants from the grind and place the tube on your workbench.

**NOTE: Use the sandpaper ONLY WET and ONLY to remove specific burrs. Do not rub the entire tube or you will rub off the anti-friction coating on the tube and cause premature bushing wear.

Check your guide and slide bushings, washers, snap rings and o-rings. If any of them show damage or excessive wear, you should consider replacing them. If they look okay, a good cleaning should do the trick. If they need to be replaced, fork bushing kits can also be sourced from ProX with the same OEM quality and affordability of fork seals.

Inspect and clean your bushings, washers, clips and o-rings. If anything is damaged, replaced, or excessively worn, consider replacing with a new bushing set. Click here to view the ProX jack kits. After cleaning the bushings, apply seal and o-ring grease to the Teflon coating of the bushings and to the inside of the oil seal and dust seal to lubricate them.

Place your sealing ball over the fork tube far enough to cover the side bushing journal. Slide the dust seal onto the tube, then the seal clip, oil seal, washer, and guide bush in that order. Remove the sealing ball and reinsert the slide bushing into the trunnion.

Carefully place the lower tube back over the dampening rod and far enough into the upper tube to allow the bushing to hold the tube in place. Slide the bushing and washer into the upper tube. Use your gasket driver to drive the washer down and into the pipe opening. Repeat this process with the oil seal, making sure you drive the seal in far enough to expose the groove for the seal clip to fit in. Place the sealing clip in the pipe, making sure the clip fits 360 degrees into the groove. Finally, use the seal driver to position the dust seal on the bottom of the upper tube.

**NOTE: It is extremely important to ensure that the sealing clip is secured in the groove. This clip holds the seal in place and prevents the lower fork tube from detaching from the upper tube.

Clamp the upper fork tube out of the vise, being careful not to tip the fork down and spill oil. Reposition the fork in the vise and clamp it by the stub axle with the fork cap angled down.

Gently compress the upper tube to expose the damping rod through the underside of the axle eyelet and place the forked end of the crown cap wrench behind the jam nut. Slowly release the tension to allow the tool to settle on the underside of the axle eyelet.

Reinstall the adjuster rod and rebound screw on the damping rod. Using the open-end wrench and socket wrench, tighten the rebound bolt until it bottoms against the jam nut.

Squeeze the upper tube towards the axle eyelet to remove the retaining tool. Thread the rebound bolt into the axle eyelet and tighten to your owner’s manual.

Reset the rebound clicker to your desired settings.

Reposition the fork in the vise with the fork cap angled up and clamped moderately tight. Use your fork cap wrench to loosen the fork cap from the upper tube. Do not completely remove the cap from the tube.

Remove the fork from the vise and place it vertically on the floor. Completely detach the fork cap from the upper tube and slide the outer tube down.

Now put a measured amount of oil in the fork. This is an estimated amount of oil based on how much oil you lost due to the leaking seal. In most cases 10-20ml of oil is sufficient, however it is important that you have the amount of oil in your fork recommended in your manual.

Slide the outer tube back up to the fork cap and thread the cap into the tube. Using the fork cap wrench in one hand and holding the fork tube in the other hand, tighten the cap onto the fork to seal the cap to the tube.

If you are replacing the seals in both forks, repeat this process for the remaining fork.

Reinstall the fork(s) and fork guard(s), brake caliper (if applicable) and front wheel to the bike. It is important to refer to your service manual for all torque specifications when tightening bolts.

Proper maintenance of your motorcycle not only ensures safety, but also the best handling and performance. While most of us wouldn’t hesitate to change the motor oil in our bikes every year, few of us consider that the front fork legs also contain oil that is constantly being worked on while riding. The rear shock absorber (or two) on your bike also contains oil, but these cannot be serviced without special tools – you can find out how some can be serviced from K-Tech Suspension for as little as £150 by clicking here. Aside from keeping the oil in your forks fresh, the seals will eventually fail. Here’s how to fix them yourself…

The oil in your forks is worked on incredibly hard, so why not replace it regularly with a quality lubricant? How do I care for my motorcycle forks? One of the main reasons fork seals become damaged is pitting and rusting on the fork post (or tube/slider) – as the tubes move up and down in the fork legs, the seals hold back the oil. But any imperfection in the chrome can tear open the seal, allowing the oil to leak out. For example, forks with gold or black nitride coatings do not suffer from the pitting of chrome forks; Damage must be checked by a specialist. Small imperfections in the chrome can be carefully removed with very fine sandpaper and a little WD-40, but if the damage is too extensive they will need to be re-chromed or replaced. When re-chroming, it’s important to hire a fork repair specialist who understands how critical tolerances are. As a general rule, keep the forks clean like the rest of your bike. Don’t be tempted to use seal cleaning tools that slide under the seal while it’s in place – these can push grit into the fork body, which gets into the damping shims and valving, often damaging the seals even more. If the dust seal that sits on top of the fork leg lets dirt through, it—and the oil seal—need to be replaced.

Pitting on fork upper tubes quickly ruptures seals How long should my fork oil, seals and bushings last? How long your fork seals and bushings last depends on how and where you ride—if you ride in very dusty areas, traverse a lot of potholes (or land a lot of awkward wheelies), they can fail in a few years. Mine were both leaking but the bike is 21 years old; It’s only traveled 18,000 miles, but it’s done nothing for nearly a decade – these seals will die off in time. Oh, and it used to belong to the ex-editor of Fast Bikes magazine, although he promises me he didn’t ride it like he’d been pressing bikes. Before that it was his mother’s bike – maybe she was a bit of a hooligan. The oil lasts a limited time and the Haynes manual shows that it should be changed every two years / 16,000 miles on this 1999 Kawasaki ZX-6R. The best way to keep your forks in peak condition is to service them. While every two years would be ideal, assuming they don’t have any issues, every three to four years (unless you’re on the track or traveling a lot) should be fine. You can service them yourself, but it’s worth knowing that the K-Tech suspension, for example, will do a full strip and rebuild with new seals for around £150. This includes the complete disassembly and cleaning of the shim stack that controls the damping, which is only possible with special tools.

Oil on the upper tubes is a sure sign of a blown fork seal. How do I know when my fork seals and bushings need replacing? The bushings wear out over time, leaving some slack between the leg and the post. Realistically, however, the first thing you’ll see is the fork seals fail, and if you replace those you might as well replace the bushings, especially since they have to come out to get the seal out. The seals are more obvious when they fail – you’ll see traces of oil on the fork supports near the dust seal; If there are any, wipe them clean and give the forks a few shakes to check it’s not just road dirt.

What parts do I need? Always replace your seals and bushings in pairs – if one leg has trouble, the other isn’t far behind. A pair of fork dust seals (the ones you can see) for this 1999 ZX-6R is £20.62 from Kawasaki, while a pair of oil seals that sit underneath are £22.08. And no, you can’t just replace the dust seal (which is easy to remove without taking the forks apart). You should also ideally replace the snap ring on each leg that holds the oil seals in place – two of these cost £5.18 from Kawasaki, while the two inner and two outer bushings add a further £45. That’s over £92 in total for OE. Fortunately, Wemoto offer complete conversion kits – you can get all the gaskets, snap rings and bushings for this bike for just £41.29. If a fork stanchion is damaged and you need to replace it, a new one from Kawasaki will cost you £244.51. A bent fork leg can sometimes be straightened, but if it is kinked it will need to be replaced. Wemoto sells Italian-made fork stanchions by Paolo Tarozzi for £140.28. You will also need oil – check your Haynes or owner’s manual for the correct weight, but it’s usually 10W. Having visited the Motorex factory in Switzerland I tend to choose their lubes so I use Motorex 10W Racing Fork Oil. This bike requires up to 592cc per leg after stripping the forks, so it took two one liter bottles at £14 each.

What tools do I need? This article is not intended to be all you need to know about changing the fork seals on a motorcycle. I’m building it on my 1999 Kawasaki ZX-6R, but your bike will have its own unique needs, so I highly recommend purchasing a Haynes workshop manual first. I hope this gives you the confidence to tackle the job yourself, but only a workshop manual specific to your machine will give you the right approach. Remember, Bennetts customers can save a whopping 40% on Haynes manuals at Bennetts Rewards. You’ll also need the following… Allen wrenches

wrench

socks set

slotted screwdriver

A tool to drive in the new oil seals and upper bushings, or a piece of tubing that fits just over the outside of the fork tube

Fork oil level tool or a vernier caliper or ruler

Fork seal and bushing installation tool or a piece of tubing that fits over the upper tube.

An impact wrench. You might be able to do without one, but you need an assistant.

brake cleaner

A suitable piece of pipe can also be used as an alternative to a seal/bushing installation tool. How do I change the fork seals on my motorcycle? You really need a clean place to work on your forks; Any dirt that gets into them during rebuilding will compromise their cushioning performance. If you want a full service on the forks I would recommend sending them to a company like K-Tech as they clinically rebuild them which involves removing the shim stacks and cleaning (you need a lathe to turn the turning forks). lock nut off). Just £150 for the service includes new seals, although you’ll have to pay for the bushings if they need replacing (they won’t cost much more). Replacing just the gaskets and bushings can get most of the suspension clean, but don’t try to remove the washers. Only work on one fork leg at a time to avoid mixing parts between the two that have worn slightly differently. Step 1: Loosen the spring preload and tighten the rebound adjuster. If you want to adjust the preload back to the original value, count how many turns you make before turning it all the way back. Also turn the rebound adjuster all the way in – this will make it easier to adjust the top cap height later.

Always avoid using an adjustable wrench if you can – that was all it took me to fit the fork caps as I loosened them up before taking them to Nick’s shop for the top triple clamp that holds them in place, and the handlebar clips (if present). Do not loosen the lower triple clamp bolts at this point. If the forks are only held by the lower triple clamp, you can loosen the fork caps – they just need to be broken open, but you mustn’t clamp the upper tubes in a vise (they could be easily deformed), so now is your last chance, you’ll do it have to. Step 3: Remove the Forks Before dropping the fork legs out, note where they sit relative to the top of the upper triple clamp. You’ve already removed the wheel, but you’ll also need to remove the fender, calipers, and anything else attached to the fork. Make sure you hang the calipers somewhere on the bike so there is no stress on the brake lines.

Step 4: Remove the bottom screw. The exact method of disassembling forks depends on the age of the bike and whether they are upside down or right side up. Having a Haynes manual is essential. Never clamp the fork support in a vise. So protect the jaws of the vise to hold the fork and keep both caliper mounts and as much of the metal that compose them as possible. Still, take care. On this ZX-6R, the left fork leg has the axle nut – remove this to access the bolt inside the fork leg that holds the damper cartridge in place. By far the easiest way to remove this bolt from a Right Way Up fork is to use an impact wrench and rattle it out. If you can’t get one, you should be able to loosen the bolt by having an assistant push the stanchion into the fork leg as hard as possible – the pressure of the spring should prevent the cartridge from rotating. Of course there is a Kawasaki tool to hold the cartridge.

Note the washer that sits on the bottom screw – this is a sealing washer and should be replaced on reassembly. If your bike has an upside down fork the disassembly method may be significantly different – check your Haynes manual.

Step 5: Drain old oil Haynes suggests a different order than stripping the forks, and if you’re unsure, it’s best to follow it. However, Nick drains the old oil from the bottom bolt hole and pumps the prop in and out. Let it sit for as long as possible to drain as much as possible. Collect it like any oil and dispose of it properly at your local recycling center.

Step 6: Remove Dust Seal Using a flathead screwdriver, carefully pry the dust seal off the top of the fork leg.

Step 7: Remove the snap ring Using a small screwdriver or a pick, remove the snap ring sitting on top of the oil seal.

Step 8: Pull out the fork stanch Again, the order varies by bike, but at this stage Nick has left the fork top attached to the stanchion because he has completely removed the bottom bolt holding the cartridge, otherwise the the fork top must be removed from the damper rod. To remove the seal on these forks, hold the fork leg and firmly pull up and out on the upper tube until the bushings internally butt and begin to drift out. You will have to do this a few times until the seal and bushing pop free and the prop is removed. Once you have removed the cartridge with the upper tube, check the underside of the fork leg where the cartridge seat is likely to still be.

Step 9: Remove bushings and gaskets. Keep an eye on how everything fits for later. First the lower bushing needs to be pryed open with a flathead screwdriver to loosen it from the underside of the upper tube, then the upper bushing followed by its washer and the oil seal can be slid off.

Step 10: Remove the cartridge from the upper tube A full service from a company like K-Tech would involve disassembling and thoroughly cleaning the cartridge itself, but that requires a lathe and some expertise. Assuming you thought to loosen the top cap with the fork leg still on the bike, unscrew it completely and slide the upper tube down. You can then hold the preload adjuster while loosening the locknut. Then remove the cap that allows you to remove the damping adjuster rod and damping cartridge along with the washer, spacer, another washer and spring (note that the smaller, tighter coils are on the bottom on this bike). Note the fit that lies between the bottom of the cartridge and the base of the fork leg – it will likely still be in the leg. Lay out all parts on a clean workbench, ideally on a paper towel.

Step 11: Fix Minor Dimples. On chrome fork stays, run your fingernail over any marks or dimples to feel for small ridges; These can be carefully sanded away with 1200 grit sandpaper and some WD-40. Take it very carefully though – stop periodically to look for the shiny area you are sanding; You only want to take off the small lip and not sand off the rest of the chrome too much. Remember, if the forks need to be re-chromed, contact a specialist who can keep the thickness just within tolerance, or the stanchion diameter may not match the seals. Heavily damaged supports should be replaced. If removing the edges leaves a hole in the chrome caused by corrosion, you should definitely replace the upper tube or have it properly re-chromed. If you’re really skinny you can try filling the damage with chemical metal and then sanding it down, but it’s not recommended. Expert Tip: Look for pitting throughout the upper tube “While there will be pitting on the painted area of ​​the fork legs, which will damage the seals used, you also need to clean the area above of rust and pitting,” says Nick Nomikos, owner and MoT Testers at The Two Wheel Center in Harpenden. “Any imperfections there will tear at the new seals if you slide them on.”

Step 12: Clean Everything Thoroughly clean all parts of the suspension with a solvent cleaner like brake cleaner, pressing a paper towel or rag in with something to clean right into the leg, being careful not to leave anything behind. If you have a compressor, blow the parts dry. Clean the seal and clip seats at the top of the fork leg with an abrasive cloth.

If everything is clean, inspect for damage, including the oil seal seat. If you don’t have an impact gauge, you can check if the fork leg is straight by rolling it on something flat like a sheet of glass. Also check the spring for signs of damage and that it is not sagging – the length it should be is in the Haynes manual; in this case it should not be shorter than 264 mm.

You can inspect the bushings for signs of wear but as the forks are apart it’s worth swapping them out, especially as they cost less than £20 from Wemoto or are part of the conversion kit we fit here. You should also check that the damper rod moves freely up and down in the cartridge – if it does not, it will need to be replaced.

Step 15: Installing the New Lower Bushing The new lower bushing must be carefully pry open with a flathead screwdriver before it can be slipped onto the bottom of the upper tube. Then wipe some of the new fork oil onto the bushing and pour a little down the fork leg to lubricate the sides.

Step 14: Reinstall the cartridge Push the cartridge all the way into the upper tube making sure the seat is down – this needs to be the right way up to mate with the bottom of the cartridge. You can now reinstall the bottom screw and washer. This should be tightened with the Kawasaki tool to hold the cartridge, but most people will tighten it with an impact wrench on a low setting. You can fully tighten it when the fork is reassembled with the spring to apply pressure and an assistant compresses it if you don’t have an impact wrench.

Step 15: Install the Upper Bushing Push the upper tube down into the fork leg as far as it will go, then wipe some fork oil onto the new upper bushing and slide it down over the upper tube until it is just above the cutout sits at the top of the fork leg. You will need an assembly tool to sink it fully or a suitable piece of tubing to fit over the stanchion. At the push of a button you could use a flat blade screwdriver to tap it home, moving it 90° with a gentle tap each time until it’s fully seated, but make sure you put the washer over the tip of the bushes before doing so. Expert tip: run bushing and seal separately “Some people run the top bushing, washer and oil seal down together,” says Nick Nomikos, owner and MoT tester at The Two Wheel Center in Harpenden. “But the extra force going through the oil seal worries me; If you do it right, it doesn’t take much more time.”

Step 16: Install the new oil seal. After checking that the washer is properly seated over the bushing, wipe some fork oil on the lip of the new oil seal and then check how it faces up. The marks should be on the top. Slide the new seal over the upper tube and down into the top of the fork leg. Using the pipe section or a gasket driver, push the gasket back into its original position until it is properly seated and the groove into which the retaining snap clip can be inserted is clearly visible.

Step 17: Attach the retaining clip and new dust seal Insert the snap clip into the groove above the oil seal (use the new one that came with the Wemoto kit if you bought this) and then check that it is properly seated by turning it. You can now run a little fork oil around the inside of the new dust seal and slide it into place. This should be pressed down by hand, but you can gently press down the edges with the side of a screwdriver shaft if needed. Step 18: Prime the cartridge There is a dedicated tool for pumping the shock rod, but you should be able to reach the rod to do this by hand. Fully compress the upper tube and damper rod, then slowly pour in the specified amount of oil – it’s at the beginning of the Frame, Suspension and Final Drive chapter in your Haynes Handbook; On this bike, 500cc is more than enough for the time being. Reach in and take the damper rod to pump it fully up and down 10 times. Then pump the standpipe up and down ten times.

Step 19: Adjust Air Gap The amount of oil you put in is not as important as the distance from the top of the upper tube. After making sure all air has been purged and the cartridge is full of oil, push the damper rod and upper tube all the way down, then measure the distance from the top of the upper tube to the oil. You can do this with a ruler or calipers, but the easiest way is with a fork oil level tool, which is basically a measuring tube with an adjustable plate and a syringe. I once made one using a narrow tube taped to a ruler and an old syringe. Add or remove oil until the air gap is as specified (in the same place in the Haynes manual). Here it is 103-107 mm. Step 21: Check the Top Cap Locknut The locknut on top of the damper rod sets the height of the cap when it is threaded down. If you turned the rebound adjuster all the way down before removing the top cap, you can use this to find the correct position and simply thread the locknut back up to meet the cap. However, if you have not done so, do not screw it all the way in now, but adjust the position of the lock nut before replacing the spring – there should be 11mm threads above the nut on this model.

Step 20: Install the spring Pull the damper rod up and then let the spring fall down over the rod with the tighter coils (this is on my 1999 bike, on the previous ZX-6R they go up so have a look in your Haynes manual). Next drop the washer, then the spacer, then the other washer. Finally, drop the damping adjuster rod back into the damper rod.

To have a look at the bushings you need to separate the outer tube from the lower one. This isn’t difficult, but I don’t think it’s necessary until a fork seal change is required.

The tubes must be pulled apart and in doing so the socket on the inside will smack the socket on the outside and push it out of the outside leg. In most cases there is very little damage and they can be reinstalled without any problems. On some bikes I have noticed a major loss of bushing material and a replacement is required.

If I personally need to make fork seals, I buy bushings at the same time. If I pull them apart and if they look great I put them back in and the new ones go on the shelf for next time. Not that expensive and when I’m done I know the forks are in tip-top shape.

This is another reason to change fork oil regularly. The older the oil is, the more metal particles are in the oil. Look at any real old oil and it will have so much metal that it shimmers when you light it. Your bushings use this as a lubricant. Keeping your oil fresh will greatly increase the life of your bushings.

If you go all the way and pull them apart I would plan for fork seals as well. I’m not a fan of reinstalling used fork seals. I’m sure others have done this with no problems, so it depends on what you’re comfortable with.

At 47k miles I’m sure your oil will be pretty black. You should definitely notice slightly better fork action with the new oil.

If you notice oil leaking from the fork tube of your motorcycle or dirt bike, it may be time to replace the fork seals. Bad fork seals can also affect your bike’s performance and handling, so get it taken care of as soon as possible.

Replacing your fork seals can cost anywhere from $50 to $500 depending on whether you do the job yourself or take it to a mechanic. The parts aren’t very expensive, so most of the cost will depend on how much you’re paying for the labor.

Replacing your fork seals can cost anywhere from $50 to several hundred dollars depending on who is doing the job. If you take your motorcycle or dirt bike to a local garage, expect to pay anywhere from $120 to $175.

You may find that the cost is much higher if you take it to a dealer or certain bike shops that charge more for the job.

Estimate for replacing fork seals

Value Garage $100-$135 Moderate Garage/Chain Repair Shop $125-$160 Dealer/Bike Shop $175-$500 Home Improvement $45-$150

The good news is that replacing the gaskets is a fairly easy task and many owners choose to do the job themselves. If you’re interested in taking the do-it-yourself approach, you could end up saving a ton of money on labor costs.

Cost of replacing fork seals yourself

If you decide to replace your fork seals yourself, you will pay a lot less than taking it to a workshop or dealer.

You only have to worry about the cost of parts, and any special tools you may need aren’t strictly necessary (but they make the job easier).

The price of the seals themselves depends on what type of bike you have and whether you are buying OEM (factory) or aftermarket parts.

A set of new seals can be as cheap as about $10, or they can be in the $40-$50 range. Most cost between $20 and $30 if you order them from an online retailer.

Here’s what you need to replace your fork seals Fork seals (2)

dust seals (2)

Fork oil (2 liters)

Fork seal driver (optional but recommended)

Fork spring compressor (optional but recommended)

DIY fork seal replacement cost

Total parts cost (without tools) $35-$75 Total parts cost (with tools) $100-200

The time investment in this project mainly depends on how familiar you are with working on the bike and whether you use the tools to make the job easier. Most people spend between two and six hours changing their fork seals.

What is a fork seal?

Fork seals usually refer to the seal kits in the fork of your motorcycle, dirt bike, or bicycle. The fork seals inside the fork are designed to keep the oil inside.

The visible seals on the fork are dust seals and are designed to keep dirt, dust and debris out of the fork. Most people replace all the seals at the same time.

If your fork seal fails, there’s a good chance the dust seal didn’t do its job.

One of the main reasons for seal failure is that dust and dirt particles enter the fork, creating an incomplete seal and allowing oil to leak out.

When to Replace Your Fork Seals

If you observe a leak from the fork seals, it means they need to be changed immediately. You can also change the seals as a precaution. It is recommended that the fork seals be serviced or replaced after 40 hours of riding.

Most owners wait until there is a problem with the fork seals, but by being proactive in addressing this issue, you can avoid dangerous situations.

If you’re using your bike for racing, it’s even more important that you keep up with this type of maintenance.

If you don’t drive often, you should change your seals at least every two years. So if you don’t reach the 40 hour mark within two years, change the seals anyway.

If your bike sits idle for too long, the seals can eventually dry out and crack, causing leaks.

Signs and symptoms of a bad fork seal

The most obvious sign of a leaking fork seal is when you notice oil leaking from the area. Even if you don’t see the oil right away, you’ll likely see a buildup of dirt and grime as the oil mixes from dirt and dust making contact.

You may also notice a small puddle of oil under the fork of your bike while it is parked. Leaking too much oil and getting the oil level too low can cause your suspension to behave differently.

Many riders feel these small changes in their bike’s handling and then look for the oil leak.

Leaking too much oil can create a dangerous situation, so it’s important to be aware of this issue and never ride with a blown fork seal.

Causes of fork seal damage

Motorcycles and dirt bikes put a lot of strain on your fork seals due to the way the vehicle is built.

If you ride your bike harder than the average commuter, e.g. B. if you ride your bike off-road or participate in races, you can put additional stress on the fork seal.

One of the big challenges associated with the fork and seals is keeping dirt and debris out. Driving off-road or on unpaved roads and trails can exacerbate the problem and wear out the seals even faster.

In addition to general wear and tear, dirt, dust, sand, and other debris can get into the fork tube.

If dirt particles get between the gasket and the pipe itself, the gasket will no longer be a tight fit in the pipe, resulting in a weak seal and leaks.

Servicing your fork seals

Keeping your fork seal clean and tidy will prolong part life and keep your bike performing at peak performance.

In addition to regularly rinsing dirt and debris off the machine, you should also periodically inspect your forks and clean the seals.

The best way to save some money on potential repair costs is to perform preventive maintenance to prevent breakdowns.

To clean your fork seals, you should have the following items available: Alcohol based suspension cleaner

rags or shop towels

flathead screwdriver

Choose

8mm T-handle

suspension grease

Allen key or socket wrench

Overall, you’re only looking at $35 or less for these materials, but the result will be worth it if you’re avoiding damage to your bike.

How to clean your fork seals

Follow these steps to clean and inspect your fork and dust seals:

Remove fork guard. Use an Allen key or socket wrench for this task. Remove the fork seal. Use a flathead screwdriver to gently wiggle the gasket down. If necessary, you can use a pickaxe. Clean the inside of the joint. Clean the inside and around the joint with your alcohol-based cleaner. You can also use compressed air to blow away dust and dirt. Pump the fork. Pump the fork up and down, then spray cleaner to remove any hidden debris. Clean the fork seal. Use your alcohol-based cleaner to gently clean the seal. Lubricate the dust seal. Use a very small amount of lube. Reattach the dust seal. Simply slide the dust seal back into place.

The final result

Replacing your fork seals is a necessary task for the regular, routine maintenance of your bike. If you ride your bike hard, riding it off-road or racing, you may need to check your seals more frequently.

Many people wait until they see a leak to look at their fork seals, but prevention is key to avoiding performance problems.

The good news is that replacing your fork seals is a fairly inexpensive job and many owners do the job themselves. If you buy a set of seals online, you can get them for under $40.

If you take your bike to a shop or workshop you will end up paying quite a bit more. You also need to consider time when deciding whether to do the work yourself.

It can take an inexperienced person several hours to change the seals. So if you’re someone who values ​​your time more than the cost of the work, you might prefer to take the bike to a shop.

Keeping your seals in good condition will help prevent oil leaks and damage, and ensure your suspension is working properly.

Establish a routine to regularly clean and inspect your seals for damage to keep your bike in tip-top shape.

Leaking fork seals may seem like a minor problem, but it can lead to further damage to the internals of your fork and even to riding and braking safety. In this guide, we’ll go through every step you need to know to replace oil and dust seals on your bike.

Keeping an eye on leaking fork seals is crucial to maintaining optimal suspension performance. Remember that an improperly working suspension is a safety hazard.

Whether you’re out with friends or out on the track on race day, leaking seals can ruin any riding day, especially if that blown seal is on the brake side. If your forks’ seals are just leaking or barely holding oil, your forks aren’t damping or springing like they should. The oil helps create bottoming resistance, allowing the fork to stay in the stroke it is meant to perform.

Most current generation forks contain a closed cartridge that houses the damping and rebound valve as well as the oil. The outer chamber houses the fork spring plus additional oil. When the main fork seals burn out, the oil in the outer chamber leaks out.

If oil seeps down through the seal and down the lower leg, dirt and debris can adhere to the tube. The initial size of the crack in the seal may be small and somewhat imperceptible, but after dirt gets past the dust wiper, it damages the seal itself, causing the oil to leak out faster.

Not only do you have to disassemble your fork this far for a seal change, but it helps visualize the components inside your fork and where the oil is leaking.

Leaking fork seals that are not fixed can allow dirt to seep through the interior of the fork, likely leading to more damage and potentially costly repairs.

Replacing fork seals can generally be performed in a well-equipped workshop using some standard tools and supplies, as well as some readily available specialty tools.

It is important to note that different suspension manufacturers have different methods of disassembly and reassembly. Therefore, always refer to your owner’s manual for specific instructions for your application. This guide is intended as a general guide and not all steps are the same in all applications.

In this step-by-step guide we replaced the fork seals on a set of used Showa cartridge closed forks on a 2007 Honda CRF 450R. For the purposes of this guide, we’re going to focus on a simple seal replacement to get you back on the track or trail rather than a full outer chamber cleaning and seal replacement.

The first step before beginning any repair is to make sure you have the right tools in your arsenal and a set of new gaskets to install. Attempting to “macgyver” things with the wrong tools can easily lead to more repairs and higher costs for you. Below is a list of the tools we used for this project:

Make sure you have the right tools and a clean workspace before you begin. Special hanging tools are readily available online.

47mm ProX fork seal kit

Torque wrench (recommended by a reputable company for accuracy)

Socket wrench (drive 3/8)

8mm socket or 8mm T-handle wrench

10mm socket or 10mm T-handle wrench

17mm, 19mm, 21mm bushings

17mm open end wrench

5mm allen key

Clevis Wrench

#2 flathead screwdriver

47mm fork seal ball

48mm fork seal driver

Grease seal and O-ring

5W fork fluid (or whatever your manual recommends)

pen and paper

600 grit wet/dry sandpaper

Workbench vise with rubberized jaws

oil pan

Suspension-specific cleaning chemicals (e.g. Maxima Suspension Clean)

Awesome Orange (diluted with water 50/50 mix)

Microfiber towels

**NOTE: Tool sizes may vary by suspension manufacturer.

There are many options when purchasing new seals. OEMs are great but can be overpriced. ProX oil seals and dust seals are made in Japan by the same OE suppliers to meet OEM quality without the price tag. They are available both individually and as sets.

Prepare your new seals before disassembly. Find HERE ProX seals for your bike.

It’s always a good idea to start with having all your tools on a clean workbench or table. Start by putting your bike on a stand and removing your front wheel and then your forks. Be sure to remove the fork guards and caliper (if applicable) before loosening the triple clamps and removing the forks completely.

Remove your front wheel, fork guard and caliper (if on the brake side) before removing the fork from the triple clamps.

Check your rebound clicker settings with a flat head screwdriver and make a note of them. To do this, turn the clicker clockwise and count each noticeable notch until it stops. Once it stops, don’t force it. The number of clicks is your setting. You will need to reset to this after reassembling your fork.

If you don’t know where your clickers are set, it’s a good idea to check and record them so you can reset them when you reassemble them.

Now that the clicker settings have been recorded and the fork(s) have been completely removed from the bike, we can begin replacing the seals.

Place the fork in the vise by clamping it at the axle eyelet.

Using a socket wrench/socket, completely loosen the bottom bolt under the axle eyelet.

Be careful with this step, it can be a bit tricky. Once the bottom bolt is loose you need to compress the fork by pulling the top of the fork towards the axle tab.

With the fork compressed and the damping rod exposed, use the open end of the open-end wrench to slide the damping into the center of the “U” shaped prongs behind the locknut and slowly rebound the fork to lock the tool against the axle while dragging.

You will need an open-end wrench, a socket wrench, and two hands for this step. Place the open end wrench on the jam nut and the socket wrench on the rebound bolt and loosen the rebound bolt. Remove the rebound bolt along with the inner adjuster rod from the damping rod.

Compress the upper tube toward the down tube to remove the crown cap wrench from the damping rod jam nut and release the spring tension.

Remove the fork from the vise, being careful not to spill oil, and reposition the fork in the vise so that the upper fork tube is moderately clamped and the top of the fork is tilted down. It is important to clamp in the middle of the pipe where it is roundest and has no taper. Here the lower triple clamp holds the fork.

Use your flathead screwdriver to separate the dust seal from the upper tube. Then, also using the flat head, remove the inner seal clip from the groove in the upper yoke.

Use the flat head to separate the dust seal from the upper tube and remove the seal clip (second photo). With these parts removed from the tube, grasp the lower tube with one hand and the upper tube with the other. Slide the lower tube into the upper tube, then quickly pull the lower tube away from the upper tube with enough force to separate the two tubes, leaving the oil and dust seal on the lower tube.

Remove the slide bushing, pilot bushing, washer, oil seal, seal clamp and dust seal from the top of the down tube and place them on the workbench in the order they were removed. It is also very important to note how the oil seal was positioned. Incorrect positioning will not seal the oil.

Clean your down tube with a clean microfiber and inspect the tube for dents and sharp burrs that may have caused the seal to leak. If nicks and burrs are found, use the 600 grit wet/dry sandpaper lubricated with the cleaning slurry to remove any sharp edges. Wipe the tube with a clean microfiber cloth to remove any contaminants from the grind and place the tube on your workbench.

**NOTE: Use the sandpaper ONLY WET and ONLY to remove specific burrs. Do not rub the entire tube or you will rub off the anti-friction coating on the tube and cause premature bushing wear.

Check your guide and slide bushings, washers, snap rings and o-rings. If any of them show damage or excessive wear, you should consider replacing them. If they look okay, a good cleaning should do the trick. If they need to be replaced, fork bushing kits can also be sourced from ProX with the same OEM quality and affordability of fork seals.

Inspect and clean your bushings, washers, clips and o-rings. If anything is damaged, replaced, or excessively worn, consider replacing with a new bushing set. Click here to view the ProX jack kits. After cleaning the bushings, apply seal and o-ring grease to the Teflon coating of the bushings and to the inside of the oil seal and dust seal to lubricate them.

Place your sealing ball over the fork tube far enough to cover the side bushing journal. Slide the dust seal onto the tube, then the seal clip, oil seal, washer, and guide bush in that order. Remove the sealing ball and reinsert the slide bushing into the trunnion.

Carefully place the lower tube back over the dampening rod and far enough into the upper tube to allow the bushing to hold the tube in place. Slide the bushing and washer into the upper tube. Use your gasket driver to drive the washer down and into the pipe opening. Repeat this process with the oil seal, making sure you drive the seal in far enough to expose the groove for the seal clip to fit in. Place the sealing clip in the pipe, making sure the clip fits 360 degrees into the groove. Finally, use the seal driver to position the dust seal on the bottom of the upper tube.

**NOTE: It is extremely important to ensure that the sealing clip is secured in the groove. This clip holds the seal in place and prevents the lower fork tube from detaching from the upper tube.

Clamp the upper fork tube out of the vise, being careful not to tip the fork down and spill oil. Reposition the fork in the vise and clamp it by the stub axle with the fork cap angled down.

Gently compress the upper tube to expose the damping rod through the underside of the axle eyelet and place the forked end of the crown cap wrench behind the jam nut. Slowly release the tension to allow the tool to settle on the underside of the axle eyelet.

Reinstall the adjuster rod and rebound screw on the damping rod. Using the open-end wrench and socket wrench, tighten the rebound bolt until it bottoms against the jam nut.

Squeeze the upper tube towards the axle eyelet to remove the retaining tool. Thread the rebound bolt into the axle eyelet and tighten to your owner’s manual.

Reset the rebound clicker to your desired settings.

Reposition the fork in the vise with the fork cap angled up and clamped moderately tight. Use your fork cap wrench to loosen the fork cap from the upper tube. Do not completely remove the cap from the tube.

Remove the fork from the vise and place it vertically on the floor. Completely detach the fork cap from the upper tube and slide the outer tube down.

Now put a measured amount of oil in the fork. This is an estimated amount of oil based on how much oil you lost due to the leaking seal. In most cases 10-20ml of oil is sufficient, however it is important that you have the amount of oil in your fork recommended in your manual.

Slide the outer tube back up to the fork cap and thread the cap into the tube. Using the fork cap wrench in one hand and holding the fork tube in the other hand, tighten the cap onto the fork to seal the cap to the tube.

If you are replacing the seals in both forks, repeat this process for the remaining fork.

Reinstall the fork(s) and fork guard(s), brake caliper (if applicable) and front wheel to the bike. It is important to refer to your service manual for all torque specifications when tightening bolts.

Leaking fork seals are the most common reason for fork tearing apart. Once you get to the point of removing the seals yourself, it can be a bit of a pain. Often the seals can get stuck in the outer tube. Here’s a great tip on removing fork seals to save time.

The secret to get you out of this difficult situation is heat. By applying heat you stretch the metal tube around the seal and slide it right out. Take a propane torch and heat the outer tube surrounding the gasket. I apply heat until only a tiny bit of smoke comes out of the tube (oil residue burns off). This applies enough heat to loosen the seal, but not too much to burn the anodizing on the tubes or the seal itself.

Take a large screwdriver and slowly pry the seal out. You will find that the seal slides out without much effort. After you have cleaned and inspected the gasket, you can reheat the pipe to facilitate gasket installation.