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Changing Fork Oil

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Hi guys,

When changing the fork oil after break in, is it necessary to disassemble the whole fork or can I just remove the cap, drain, and refill? Also, I will eventually have to change seals and bushings on these forks which will someday require a full tear down; will I need a fork compressor to work on these forks or is there another way to do this?

Thanks for your help!

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If there was no leak, you can try with the same seals.

In youtube you will find a lot of videos for - how to replace fork oil.

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8 hours ago, Rockinar said:

Thanks, I saw this in my owner's manual too. Looks like I'll have to completely disassemble to clear that inner cartridge. I was hoping to avoid it this time around :)

4 hours ago, phatsmall said:

If there was no leak, you can try with the same seals.

In youtube you will find a lot of videos for - how to replace fork oil.

Thanks. I was hoping to reuse seals and bushings this time since these forks are brand new off the floor. The manual just says to change the oil after break in.

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If you don't have many hours on these forks, it will be ok.

If it is possible to dissasemble the forks and clean all parts, also the seals would be great, if not it will be acceptable as well :), nothing that could stop you riding.

Edited by phatsmall

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Sounds good, thanks guys. Since the bike is new, I know it's important to flush this oil out pretty soon after breaking in. I was thinking of trying to get around 5-8 hours on these forks before rebuilding them. I suppose while I'm in there I'll just do the job right and replace seals and bushings too. The only thing holding me back right now is buying that spring compressor tool... It's not cheap :)

Thanks!

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I changed my shock and fork oil after break in as well. The compression side can be done easy enough, but the spring side will require a spring compressor. I messed with it for a little bit but theres no way that thing was going to come apart without being compressed properly. I ended up taking that to the shop. Cheap labor for 1 fork oil change with supplying them the oil.

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1 minute ago, GasMixer44 said:

I changed my shock and fork oil after break in as well. The compression side can be done easy enough, but the spring side will require a spring compressor. I messed with it for a little bit but theres no way that thing was going to come apart without being compressed properly. I ended up taking that to the shop. Cheap labor for 1 fork oil change with supplying them the oil.

Nice. I may have to give my local shop a call and see what they charge for a single fork. Curious thought: how long do you think the spring compressor tool will take to pay itself off? Around here, it seems like it could pay for itself after 3 seal changes. Assuming the forks are done ever 25 hours or so, it may not take too long to make itself worth it. Just some thoughts.

This is always my great debate between going into the shop or buying the tools to do it myself :)

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I forgot how much a few of them i saw cost, but i think the same way when it comes to buying tools. It might take a few uses to pay for itself like you mentioned, but it would be worth it in the long run. I want to pick one up but i didnt feel like dropping the money at the time

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What year KX250F do you have? If you have the SFF v2 with 48mm stanchions, you do not need a fork spring compressor.

Using a ratcheting tie down strap, put one end of the strap on the anodized blue or green fork cap. Place a rag in-between the cap and strap hook as to not gouge the cap. On the other end of the fork, place a nylon loop strap through the axle hole. I used a "soft tie down strap loop" that is commonly used to not gouge handlebars when using a tie down. Affix the hook of the other end of the ratchet strap to this nylon loop. Now you can ratchet the strap and compress the spring, exposing the damping rod and the locknut you need to remove in order to disassemble the fork. This method works fine to re-install the damping rod's locknut too.

 

If you have a 2011 or 2012 KX250F, you can try make a homemade PVC fork spring compressor like this guy did. 

home made fork spring compressor

 

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Thanks guys. I ended up coughing the $150 for Race Tech the spring compressor tool. I figured for a machine that cost a few thousand, I should make sure I use the right tools to avoid damaging anything xD

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I have two 2005 kx250f. Both bikes have at least one fork seal weeping. How much time do I need to set aside to take the forks off the bike, take the forks apart, replace the seal, and put it all back together. ?

How long does it typically take?

 

Or maybe I just pull the 4 forks off and bring them to the kawi shop. How much would they charge in labour per fork.

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On 4/8/2017 at 1:06 AM, FaceDeAce said:

I have two 2005 kx250f. Both bikes have at least one fork seal weeping. How much time do I need to set aside to take the forks off the bike, take the forks apart, replace the seal, and put it all back together. ?

How long does it typically take?

 

Or maybe I just pull the 4 forks off and bring them to the kawi shop. How much would they charge in labour per fork.

I'm about to start pulling my forks off now that I've passed the break in period on the bike. I've read that when you "know what you're doing" you can probably get your forks done in around an hour (remember, there is a period of at least 20 minutes to drain the forks upside down). Similarly, I've also read that a lot of people take a bit longer on their first time (but after that it should be relatively straightforward).

I guess I can let you know soon :)

I don't think the 2005's have the Showa SFF's do they? If they're standard forks (similar to my '99 YZ250), rebuilding doesn't take too long (again refer to comments above). It seems on any bike with the SFF that the left fork would be easier to replace everything than the right if only because of the spring and cartridge. I would take a look at some videos on YouTube and you could probably decide for yourself easily enough whether or not it is worth it for your to do the work or pay someone to do it!

Edited by RageD

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I would like to know the time in the situation where: .... the forks are out.  After the forks are off the bike and forks are laying on the table, what is average for how long it takes to take one apart, replace the seal and bushings, recharge with oil and put fork back together and back onto the table.  If it is a 20-30 minute per fork I will bring the fork tubes to the shop and give them the business.  If time is much longer, I will do it myself.  With four of them to do, amongst other things, it is a time budget and dollar budget balancing thing.   I have experience doing shocks, I just haven't done these ones yet so I am not certain of what type of cartridge it is, how many bits and pieces are inside them and how many steps are involved.

Let me know how you make out please.

(2005 KX250F)

Edited by FaceDeAce

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Started doing this today. Took me about 10 minutes to pull the forks off the bike and drain the oil from the outer tube.

 

I had to leave for work, but was thinking: I only have a clamp-based vise. We'll see how it goes but I'm not sure it's going to hold for me to open up the assembly at the bottom to get at this piston rod since it's tightened down to around 58 or 59 ft-lb. We'll see.

 

So far, though, the process is straight forward. Assuming no more complications after opening up, I bet it will only be another 20-30 minutes of actual labor on the dampening fork (not including a 20 minute drain).

 

I cannot yet say anything for the spring fork of course, but if it's similar in labor, it would probably be less than an hour per fork (and I've never done any forks newer than '99 before so these are different ).

 

Hope that helps!

 

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I did one bike complete start to finish last night; took 3 hours.  That included driving the bike in, putting it on the stand, taking it all apart, doing the work, put back together, then driving it back out to the trailer.  The work included removing the two forks and the rear shock.  New seals and new oil in both forks.  New oil in rear shock.  Putting it all back together.    What took the longest was getting the oil out of the cartridge of the fork.  hold the fork upside down over a bucket.  Pump the cartridge.  Kind of like milking a cow into the bucket haha.  Keep going until there is no resistance left and nothing but air.   I do not believe that just leaving it sit to drain on its own will work.

PS:  Just remove the top cap and spring.  Flip it over and pump it.  Then refill and reassemble.  Did not have to disassemble the base of the fork, not on these one I have at least.

 

Edited by FaceDeAce
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How did you get to the inner cartridge without disassembling the fork? That may work on the right fork, but I certainly can't get to that inner cartridge without disassembly.

Lacking a proper bench vise (and assuming my landlord wouldn't like me drilling into his counter tops...), I may be forced to head to the shop anyway :(

Any last minute tips you guys may have to remove the bottom of the Showa SFF without a vise?

Going to call the shop in the morning.. Sad, I actually wanted to do this :)

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Both forks on this beast here are the same, each side. Yours may be different.

 

I did them basically the same but slightly different than Matt's video here.

 

When you do not have a vice it is amazing how effective an air impact is at breaking free nuts and bolts with your bare hands. Another trick is to break loose the caps and nuts and bolts while the shocks are still on the bike being held by the clamps and the wheel axle. If it is already out, put the wheel axle in the bottom of the fork. Lay it on the down on the floor so the axle stops it from rotating put your knee on top of the fork tube next to the axle and torque away. Of course put a board or a mat of thick towels under it to protect the floor and keep your landlord happy.

 

 

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Both forks on this beast here are the same, each side. Yours may be different.
 
I did them basically the same but slightly different than Matt's video here.
 
When you do not have a vice it is amazing how effective an air impact is at breaking free nuts and bolts with your bare hands. Another trick is to break loose the caps and nuts and bolts while the shocks are still on the bike being held by the clamps and the wheel axle. If it is already out, put the wheel axle in the bottom of the fork. Lay it on the down on the floor so the axle stops it from rotating put your knee on top of the fork tube next to the axle and torque away. Of course put a board or a mat of thick towels under it to protect the floor and keep your landlord happy.
 
 
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Yeah mine are a bit different on this bike-- those look much similar to the ones on my yz. I haven't had much of a problem with those in the past but these are a bit less friendly :(

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