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Hello, I have a fairly new kx250f with 20hrs and every time I ride it my forks leak. The only way to stop the leak is by Motion Pros seal mate tool. What might be wrong? Thx

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Dirt under seal lip , nicks on fork tubes, seals damaged from muck on tubes

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12 hours ago, mog said:

Dirt under seal lip , nicks on fork tubes, seals damaged from muck on tubes

Is it safe for the suspension riding it like that or do I have to replace as soon as possible?

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16 minutes ago, Alex_3401 said:

 

Is it safe for the suspension riding it like that or do I have to replace as soon as possible?

Any maintenance item left go for long enough becomes a safety issue on a dirt bike. You need to determine the cause and resolve the issue. No way for us to know how much oil you lost and what kind of riding you do. But at some point the suspension will be wonky enough to be an issue.

Dirt under seal: Could just be that you rode in dirty/sloppy conditions, got dirt on your forks and under your seals. It's a dirt bike, dirt under the seals, it happens. What doesn't happen is sometimes people don't include cleaning under the dust seal periodically as part of their maintenance. If at the track, clean your forks between motos if necessary, etc.

Nicks (or otherwise damaged) fork tubes: you should be inspecting your fork tubes as part of your maintenance. Having 20 hours on the forks is about when I do an fork oil change but I run 100% track. I sometimes go longer but if this is the first fork oil change at 20 hours I'd do it now. Having the forks off the bike is a great time to do the overall inspection.

Seal damage: If you can't get the seals to "seal" again after cleaning under them could be a few things - 1) you didn't clean good enough; try again. Having to try a couple times is not uncommon. 2) you got enough dirt in the oil it keeps happening. Just an oil change may fix. This is more likely of you get the seals working again but they start leaking shortly there after. 3) Your seals are actually shot. Good news is that they are not that hard to replace. Many of us replace them occasionally as a wear item; honestly seals last a pretty long time for what they cost.

If it were happening to me - every time, even if the bike did not get that dirty (clean fork legs) - I'd just go ahead and replace the seals while doing an oil change. The service manual will also call out other items to be inspected while performing service on the forks.

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OP,

Replace the seals and inspect the bushings while you're in there.

After 20 hours, those new forks have broken in and the oil likely contaminated with fine metal particles and Teflon bushing material.

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Any maintenance item left go for long enough becomes a safety issue on a dirt bike. You need to determine the cause and resolve the issue. No way for us to know how much oil you lost and what kind of riding you do. But at some point the suspension will be wonky enough to be an issue.
Dirt under seal: Could just be that you rode in dirty/sloppy conditions, got dirt on your forks and under your seals. It's a dirt bike, dirt under the seals, it happens. What doesn't happen is sometimes people don't include cleaning under the dust seal periodically as part of their maintenance. If at the track, clean your forks between motos if necessary, etc.
Nicks (or otherwise damaged) fork tubes: you should be inspecting your fork tubes as part of your maintenance. Having 20 hours on the forks is about when I do an fork oil change but I run 100% track. I sometimes go longer but if this is the first fork oil change at 20 hours I'd do it now. Having the forks off the bike is a great time to do the overall inspection.
Seal damage: If you can't get the seals to "seal" again after cleaning under them could be a few things - 1) you didn't clean good enough; try again. Having to try a couple times is not uncommon. 2) you got enough dirt in the oil it keeps happening. Just an oil change may fix. This is more likely of you get the seals working again but they start leaking shortly there after. 3) Your seals are actually shot. Good news is that they are not that hard to replace. Many of us replace them occasionally as a wear item; honestly seals last a pretty long time for what they cost.
If it were happening to me - every time, even if the bike did not get that dirty (clean fork legs) - I'd just go ahead and replace the seals while doing an oil change. The service manual will also call out other items to be inspected while performing service on the forks.


What tools would i need to replace the seals?
Do i have to take all the suspension out, if so do i have to align when i re install them?
Do i have to break in the new oil?

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13 hours ago, Alex_3401 said:

 


What tools would i need to replace the seals?
Do i have to take all the suspension out, if so do i have to align when i re install them?
Do i have to break in the new oil?

 

First and foremost you'll need the service manual for your bike. Maybe you can find your service manual on Tradebit for cheap (pdf version). Typical tools (socket set, etc). A couple speciality tools make life easier (seal driver, fork cap wrench). In your case I guess you may need the spring compressor. A lot of times you can figure out how to do things without the specialty tools but then other times they save you a lot of grief.

Yes, you have to remove front wheel/forks and align. Alignment is easy. Found a youtube video on the subject - https://www.youtube.com/watch?v=6LtDZrSsu2U

May not be your forks but procedure would be very similar. Watch these two youtubes and you will have an idea of what needs to be done.

https://www.youtube.com/watch?v=vrafDhaHbKc
https://www.youtube.com/watch?v=rGjUpxEMrT0

A couple videos from RockyMountain:

https://www.youtube.com/watch?v=JEhBw3Ww75U
https://www.youtube.com/watch?v=nF62s4r6V8k

Don't have to break in fork/shock oils and seals; just go ride.

What year bike you have?

Edited by GoneDirtBikeN

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First and foremost you'll need the service manual for your bike. Maybe you can find your service manual on Tradebit for cheap (pdf version). Typical tools (socket set, etc). A couple speciality tools make life easier (seal driver, fork cap wrench). In your case I guess you may need the spring compressor. A lot of times you can figure out how to do things without the specialty tools but then other times they save you a lot of grief.
Yes, you have to remove front wheel/forks and align. Alignment is easy. Found a youtube video on the subject - 

May not be your forks but procedure would be very similar. Watch these two youtubes and you will have an idea of what needs to be done.


A couple videos from RockyMountain:


Don't have to break in fork/shock oils and seals; just go ride.
What year bike you have?


2016 Kx250f

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For installing the forks would i need a special tool in order for them to go back in straight ?

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6 minutes ago, Alex_3401 said:

For installing the forks would i need a special tool in order for them to go back in straight ?

Nope. The one video show compressing the forks before tightening the right hand side axle bolts. I prefer the method to spin the front wheel and sharply grab the front brake. I like my way but then again I do the work while the bike is on a lift. Read though the manual and decide which special tools you could do without. For example I don't have the fork cap wrench that I can use the torque wrench with; so I tighten the fork cap by hand.

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Nope. The one video show compressing the forks before tightening the right hand side axle bolts. I prefer the method to spin the front wheel and sharply grab the front brake. I like my way but then again I do the work while the bike is on a lift. Read though the manual and decide which special tools you could do without. For example I don't have the fork cap wrench that I can use the torque wrench with; so I tighten the fork cap by hand.


So during this process the triple clamp bolts have to be loose right?

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5 minutes ago, Alex_3401 said:

 


So during this process the triple clamp bolts have to be loose right?

 

You loosen the pinch bolts - forks drop right out. But you want to loosen the fork cap before you remove the forks from the clamps - You might need to remove the handlebars to provide access to do this.

13 minutes ago, Alex_3401 said:

 


Do i have to the any maintenance to the rear suspension?

 

Pretty much same story as forks. Here's a couple videos to reference.

https://youtu.be/0_InEnom2ec?list=PLxR86UD-Ub2qHTiFS57VUDsLhhV0bLQSP

https://youtu.be/B3faPx7Vw-8?list=PLxR86UD-Ub2qHTiFS57VUDsLhhV0bLQSP

 

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I found a seal protector called shock socks. Are they recommended or do they affect suspension performance ?

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I found a seal protector called shock socks. Are they recommended or do they affect suspension performance ?

I have a set and I like them. Just take them off when you wash your bike. I hose mine off and let air dry and reinstall. You just don't want any accidental dirt to be trapped behind them gritting up. I haven seen any dirt on or near my seals since installed. I got the Velcro ones.
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