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  #1  
Old 08-31-2007, 10:09 AM
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Default '04 YZ250F fork seal replacemnt..Help!!

     

I am about to change my fork seals in my '04 250F and have seen some confusing things on all my research to do this correctly...

First I do not think I need a Fork Cap Wrench...the top of my forks just have a 19mm hex type knob with an air bleeder screw(I think next to it)..so I do not need a 55mm Fork Cap Wrench correct?

2. I think that yamaha went to USD Twin chamber forks back in 2003...I read here that someone said they did nt go to twin chamber until 2005? so which is it?

3. All my research tells me that in order to get the seals out you need to totally dissemble the forks...I have just read that some people have done it with out taking the inner chamber out? so which is it?

4. I do not have an 04 manual...anyone have one in a PDF file that I could take a look at?

5. So what tools will I need to get this accomplished exactly...my biggest wrench is a 18mm...will I need a 19 and a 35mm which I read somewhere?

Thanks in advance..

Ride Fast, Take Chances!!!

Scotty J.
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  #2  
Old 08-31-2007, 09:33 PM
basanch73's Avatar
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Default Re: '04 YZ250F fork seal replacemnt..Help!!

Sounds like you have the same type forks as my 01 YZ426F. I just serviced my forks and shock this past week. Here's the manual link from satch's general KB post to get you started: Yamaha Owner's Manual Library

Be sure to bleed the forks first and write down your clicker settings before turning them all the way out. You'll need the 19mm wrench or suitable adjustable for the top caps. Next I used a smaller wrench (I think a 17mm) to break loose the nut under the spring at the top to get the cap free and to remove the spring. I then drained out the old oil. I then secured it back into the lower clamp to hold the upper tube in place for the next step. To remove the shaft I used a small screwdriver to pry and slide the wiper seal down the shaft to expose the snap ring that holds the seal and shaft in place within the upper tube. Just be real careful not to scratch the shaft. With the ring removed, I had to slowly slide the shaft up into the tube a little and then drive it down a couple of times to free it. I ended up replacing things with the total rebuild kit for $75 and 1 quart of $8 (5w) fork oil. You'll need to cover the upper bushing and groove before you slide the wiper and seal down over it to keep from damaging them. I used tape. You'll also need a seal driver to get the shaft and seal back into place in the tube. I used PVC tube cut in half. I never went further than that and just filled it up to the proper level with my home made oil level gage from a coat hanger with my measuring marks scribed onto it. Not sure if I should have went further on my rebuild, but they work like a charm now.

The manual gives great directions on the fork rebuild, but not the shock; however, the suspension forum took care of that. The shock is way easier, but a little more messy.

Good Luck,

Brian


Quote:
Originally Posted by ScottyJFZ1 View Post
I am about to change my fork seals in my '04 250F and have seen some confusing things on all my research to do this correctly...

First I do not think I need a Fork Cap Wrench...the top of my forks just have a 19mm hex type knob with an air bleeder screw(I think next to it)..so I do not need a 55mm Fork Cap Wrench correct?

2. I think that yamaha went to USD Twin chamber forks back in 2003...I read here that someone said they did nt go to twin chamber until 2005? so which is it?

3. All my research tells me that in order to get the seals out you need to totally dissemble the forks...I have just read that some people have done it with out taking the inner chamber out? so which is it?

4. I do not have an 04 manual...anyone have one in a PDF file that I could take a look at?

5. So what tools will I need to get this accomplished exactly...my biggest wrench is a 18mm...will I need a 19 and a 35mm which I read somewhere?

Thanks in advance..

Ride Fast, Take Chances!!!

Scotty J.
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  #3  
Old 11-02-2007, 06:02 PM
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Default Re: '04 YZ250F fork seal replacemnt..Help!!

I just replaced my twin chamber KYB fork seals following this tutorial. its really not that hard.

CR500 Riders - Suspension Stuff...

it wont be exactly like this - you will probably need different tools but if you read this then it will show you what you have to do. therefore helping you decide which tools you need.

for mine i needed a 14mm allen wrench - couldnt find one so i made one out of a bolt that i had. for the cap wrench all i did was i put the fork in a vice and held the cap with a large pair of adjustable pliers (some ppl call them "channel locks")
i dinndt use a seal driver-just lightly tapped the seal down with a very dull screw driver. the seal just has to get down far enough to expose the circlip grove. GL
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  #4  
Old 11-02-2007, 10:34 PM
Woody_YZF's Avatar
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Default Re: '04 YZ250F fork seal replacemnt..Help!!

Answers to questions 3 & 4. They did not go to the twin chambers until 2005, so you won't have to worry about the inside chamber.
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