Motorcycle Fork Seal Change Part 1 (of 2) Cartridge Type

Fork seal replacement. How to replace the fork seals on a motocross bike. This is Part 1 of our 2 Part video which covers the disassembly of the fork. Part 2 covers the reassembly of the fork and adding the correct measurement of oil into each fork leg. This instructional video of the rebuild of the Cartridge type fork which is commonly seen on late model dirt bikes. Replacing your leaking fork seals is easy and we’ll show you how to do it! Get all the parts and tools you need @!

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Title : Motorcycle Fork Seal Change Part 1 (of 2) Cartridge Type
Video Length : “04:21
Channel | User | Playlist : Rocky Mountain ATV MC
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RockyMountain MC

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  • The YZ125 has the cartridge type forks so the only special tools you would need for that would be a 46mm Fork Seal Bullet & then the 46mm Fork Seal Driver & also a Fork Oil Level Tool… & then just oil and your seals. Fork the YZ250F it comes stock with the KYB Dual Cartridge Type Forks so you will need a 48mm Fork Seal Bullet and then a 48mm Fork Seal Driver & then you would also need a Fork Cap Wrench for the outer cap, inner cap & something to hold the damper rod as well and then oil & seals

  • I need help. I have 01 zx6r I changed one fork oil already. But the right one giving me problems..I got the bottom bolt lose but won’t come out just spins. I took off top and everything inside but damper rob won’t come out and bolt at bottom won’t come out. I tried hold the rod from spinning and trying to get bolt out but just spins.

  • did you try an air impact? have a buddy pull an the fork (extending the inner and outer tube). This puts pressure on the cartridge to prevent spinning. As he does that, hit the bolt with the impact. It should spin fast enough to get it out.

  • Thanks for the great vid. I have a 06 cr125r, My manual said a partition plate(washer) should fall out when poring out the oil but I found it stuck to the spring centering washer on top of the spring. The book says it goes in the tube before the spring but it wouldn’t fit in the tube. does it have burrs or is it supposed to go on after the spring like I found it.  

    • I’m looking at the OEM diagrams on our website of the Front Fork Assembly for your bike. It looks like there’s a washer that sits below the spring which is what your service manual must be referring to but from what i can find it was commonly removed to improve oil flow. There’s also another washer that sits between the top of the spring and the centering washer which is the one you found and that washer needs to go back into the place it came out of. If there wasn’t a washer that came out after removing the spring it’s likely that washer was never in there to begin with and you can continue with rebuilding the forks

  • I have a kx250 05 that i bought to restore. The forks on it aren’t like these or like the twin chamber ones. I’ve never came across them before. could anyone give me some information on them? (I’m changed the seals on them)

    • If that bike has the stock forks on it they are the KYB 48mm Inverted forks which are a dual chamber fork. In our dual chamber fork seal replacement video we are working on a set of showa forks but process would basically be the same on these forks. You’d just need to get the Kayaba specific fork cap tool

    • Luke i was wrong about the dual chamber video. We show the KYB forks so the forks on your KX250 should be very similar to what is shown in the dual chamber fork seal replacement video.

  • I cant get my fork caps off there on so tight any suggestions? Also my rebound adjustment screw is almost completely stripped and i cant unscrew it…what would your suggestions be on that?

    • +Jacob Cramer You still have the forks in the triple clamp right? That will make it easier to break the fork caps loose initially. As for the rebound if you can’t get it to rotate at all and you can’t use a file to clean it up at all go ahead and remove the fork cap and you’ll have to get a new one to be able to put it back together.

    • +Rocky Mountain ATV MC  Where can i find the new rebound screws at for my bike i cant fint them. Thanks for the clamp trick it should be a lot easier to break them lose.

    • +Rocky Mountain ATV MC another thing im kinda wondering about you pulled a rod out of the damper i believe ? neither one of my forks had that rod ! should i be concerned?

    • +Rocky Mountain ATV MC This Happened when i was attempt to adjust the rebound damping, it’s a 04 rmz 250 and i think the previous owner disassembled the fork and made something wrong but i dont now what … please help me

    • +dagoberto ledezma
      You’ll have to disassemble the fork to figure out what is bound up inside. Just follow along with this video and your service manual and you should be able to figure out what is causing the problem.

    • +wiltch   The measuring tool makes it nice and easy to get the correct amount of fork fluid in each chamber.  Just in case you over fill your fork, you can extract it back out to the correct level needed. Its a handy tool to have to get that precise measurement. 

    • +Rocky Mountain ATV MC I do as it happens mate. Slightly off topic to forks, but i have new disc’s and pads on my KX125. The rear pads and disc rubs to a point of over heating and seizing the two together. I have to wait for it to cool down or pour some water on to help the separation process (which i hate doing). I originally put this down to the bedding in process but it’s still doing it…?
      checked to make sure my back wheel is straight and on the swing arm markings im about 3mm off on one side.
      you can visibly see the caliper being moved left to right when i raise the bike and free wheel it…. The disc appears to be straight and not warped, no crashes etc…
      Having to resort to finding the OEM disc tomoz to change it back as i want to ride and there were no issue’s before hand.

      Any suggestions ? 

      Could the pads still need bedding in ??
      Could disc be slightly warped that my eye cannot see ?

      Also, Bikes had about 3 hours use since they were changed.

      Many thanks in advance, What time are you guys on ?
      Respect from the UK

  • Hello friend MC ATV Rocky Mountain Israel my name i live in Mexico DF i want to ask a favor if you can give me the amount of oil that goes into every bar front suspension from the 1988 Honda XR250R i thank you so much

  • Do you have any videos of you doing the seals on the 2015 crf450r. I havent done the air forks and i would like to have something to follow before. Thank you

  • hello, 

    how do i know the level (depth in mm from top) that matches my bike fork? its a KTM SixDays 125cc 2011

    according to the KTM 125 owner’s manual the air chamber length is 110mm, is this the depth from top?


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