Author Topic: changing fork seals...  (Read 6329 times)

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Offline 1989kawasaki

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changing fork seals...
« on: March 18, 2011, 08:40:55 AM »
i am about to do fork and dust seals on my 89 kx250 and was wondering if there are any special tools needed to do the job?
and is there a thread on how to change the seals with step by step instructions? (i have a manual but i want to see what you guys do)

any help will be much appreciated
bikes

1977 RD400
1989 CR250
1988 CR500
1978 Z50
2009 Harley super glide custom

Offline SMPKX500

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Re: changing fork seals...
« Reply #1 on: March 20, 2011, 04:59:27 PM »
I have to do mine to. Whats the trick. How much fliud? How much nitrogen? There's not a lot of info and I have never done it either. 
500cc Thumper Smackdown!

Offline alward25

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Re: changing fork seals...
« Reply #2 on: March 20, 2011, 07:30:12 PM »
Search youtube,  There are a few how to vids that are pretty good.  For seals you will need a seal driver.  Rocky Mountain or Pit Posse have pretty good deals.
Good luck!
"Let there be light"

Offline Friar-Tuck

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Re: changing fork seals...
« Reply #3 on: March 21, 2011, 06:17:04 AM »
  Ask and you shall receive!
http://www.youtube.com/results?search_query=changing+fork+seals&aq=f

 Spending the money on the right tools was well worth it to me, and if you don't plan on doing anymore suspension work any more some one will buy them when you're done.   If money is really tight, (or you have the means to make your own tools)  the stuff you need isn't really complicated.   You can make a fork seal driver out of PVC pipe (& or Fittings)
  etc.  and an oil level gauge out of some clear tubing.
    Either way you go Take your time.  You can do it. We can Help!  :lol:
  Tuck\o/
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Offline 1989kawasaki

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Re: changing fork seals...
« Reply #4 on: March 21, 2011, 09:03:10 AM »
Thanks guys ! you're all awesome!
bikes

1977 RD400
1989 CR250
1988 CR500
1978 Z50
2009 Harley super glide custom

Offline SMPKX500

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Re: changing fork seals...
« Reply #5 on: March 24, 2011, 02:17:20 PM »
My 500 is a 04 so fairly new. Im right at 180 so I think a little stiffer is in order. I ride in Fla so mostley sand. Who has a spring guide?
500cc Thumper Smackdown!

Offline andydunne

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Re: changing fork seals...
« Reply #6 on: April 19, 2012, 02:46:10 AM »
Hey guys, just on the topic of fork seals, I am hoping to change my fork and dust seals while nursing a knee injury.
My question is, what seals would you recommend? I was looking at kits on ebay from Alls-balls etc or would OEM be best? Thanks

Offline 1989kawasaki

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Re: changing fork seals...
« Reply #7 on: April 19, 2012, 03:57:18 AM »
Oem works well in my kx . You should get oem oil seals but yu can't get OE dust seals so you'll have to get after market dust seals
bikes

1977 RD400
1989 CR250
1988 CR500
1978 Z50
2009 Harley super glide custom

Offline 1989kawasaki

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Re: changing fork seals...
« Reply #8 on: April 19, 2012, 04:48:32 AM »
Andydunne , are you talking about the 89 kx125?
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1977 RD400
1989 CR250
1988 CR500
1978 Z50
2009 Harley super glide custom

Offline Sapper

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Re: changing fork seals...
« Reply #9 on: April 19, 2012, 05:06:17 AM »
All I can say is, get the right tools. You'll use less Advil. For oil levels, an actual fork oil syphon isn't aboslutely necessary. A Ratio Rite cup will get you real close for those wanting to follow stock specs.

As for seals, I use the plain old Tusk from Rocky Mountain or the cheap ones from WPS through a friends shop. I never had an issue.

**Note**
I'm not sure of 02 and earlier, but 03-07 125/250's actually need 47.5mm seals. Yes the forks are called 48mm, but they use the stated seal.

Shocks are easy if you know the basics. i.e. let the pressure out of the bladder. Follow the service manual and you can't go wrong. Just make sure snap ring is fully seated. Otherwise you'll have a face full of oil and maybe even get hit.

As for refilling the bladder, you can use air. Nitrogen isn't mandatory, but it's more stable. If a local shop has the provisions to fill shocks, it shouldn't cost more than $10 or 15.
The problem why many don't do it themselves is the cost of the little parts and pieces needed. Plus a tank of N2, regulator, etc. Granted a small tank will fill 500 shocks easily. Otherwise, use an air compressor that is able to push out 143psi.

Offline andydunne

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Re: changing fork seals...
« Reply #10 on: April 19, 2012, 10:06:43 AM »
Andydunne , are you talking about the 89 kx125?
Oem works well in my kx . You should get oem oil seals but yu can't get OE dust seals so you'll have to get after market dust seals
Yes mate I am talking about the 89 KX125, thanks for the help. I looked at a video from rockymountainatv on youtube and i cant see it being to difficult tbh, I have a Clymer manual also to help me out!
I dont have any of the proper tools like seal drivers etc for doing it but I would like to think i can improvise when a problem arises.

Offline Hillclimb#42

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Re: changing fork seals...
« Reply #11 on: April 20, 2012, 09:54:55 AM »
A few tips, ..... loosen top triple clamp pinch bolts 1st, then break the nut loose at the top of the forks, The bottom portion of the triple clamp will act as a vise holding the tube still with no damage or stuggle. you just need to get it to break loose. Back off all of your adjustments, ( you can count and note your clicks, if you want to go back as you were before, or doing one side ) Its alot better to do both sides unless you are sure of the oil weight and amount in them from the previous build, to prevent any imbalance. You need an impact with a 14mm allen head socket, I think is the size, this is necessary to remove the bottom adjuster body.  i use a stif length of wire during re-assembly to keep the inner tube from sliding down, I also use a pvc pipe cut in about half, more like 1/3, for a seal driver. and some masking tape. You absolutely need an owners manual/ Clymer, for the first couple times, and probably again for the next time, if you do them right and it lasts. there's alot of parts that have to be in the right order, so disassemble and lay the parts out logically, but still have the manual for the oops factor.

I remove the fork from the bike after breaking the top nut loose and backing off adjustments.

Remove the top cap of the fork. its still attached to the inner rod on a threaded rod. A cheap flat wrench for a table saw blade is what I use to break loose the nut on the top of the inner tube, but a thin wrench will work good, but you will find that the fork spring's coils are too tight for standard wrench here. Once you work your way thru that deal remove the top adjuster body.

remove the spring. remove the little deal thats on the very inside of the inner tube, there's a long tube about the size of a pencil too, then dump the oil in  a container. use the inner tube to pump all of it out.

lay flat on soft surface. use the impact here on the bottom of the fork to remove the bottom adjuster body. A ratchet will not work. the whole inner tube will spin and not come apart.

pull down the dust seal. there is a big snap ring that holds your oil seal in there. take a good look at how deep the snap ring is down in there, and how it looks when all the way in the groove. It will be important for your new seal to be all the way here when you drive the new one in. 2 small...tiny flat head screwdivers working together are handy for me to remove this ring. One screwdriver is a struggle.

once the snap ring is out, you use the the outer tube as a slide hammer affect to pull the seal. You have alignment bushings that will remove the seal.

Carefully remove the alignment bushing that sets in the groove. Its a teflon coated bushing set in a groove on the inner tube. A flat head screwdriver standard size inserted in the space and gently turned will allow you to slide it up and off the tube. I use some masking tape here in the groove. Sorta fill the groove and cover the sharp shoulder of this alignment bushing groove. Use some fork oil to lube the tube and seals when reassembling.

 The order is critical and forgive me if I get it wrong and I will come back and edit. refer to manual on specific parts order and direction they face  

Slide on the dust seal, oil seal, alignment ring, remove tape, reinstall alignment bushing into its groove...... the tape is just to protect the lips of the oil seal during installation when sliding over the alignment bushing area.

I use a pvc pipe that was cut in half long ways for the seal driver. Your seal needs to go all the way past the snap ring groove. and go evenly as possible. The driver tools work much better, so be careful with the pvc idea. take your time getting the radius right and sanding all sharp corners off of it. damaging the seal is real bummin at this point cause its almost over. get the snap ring in. tap the pvc and seal in with hammer. the seal driver works like a slide hammer. be sure it looks just like it did when you removed it. Its easy to think that the seal is there and not past the ring groove.

 The dust seal just slides up into place with a little bit of a struggle. The bottom adjuster can be reinstalled to the inner rod with the impact. Again the whole assembly spins without an impact or special holding tool.

 I Use the amount of oil required in a ratio cup method also, the amount of Fluid Ounces for your bike is in the manual. pump the rod slowly to get all of the oil in there from your cup. keep pumping till the bubbles stop.

Here's where it gets tricky. You need to put your spring back over the inner rod, and get the inner rod back up to the cap. A stiff wire looped to hold up the inner rod from the inside of the spring will help to keep the inner rod up high enough to mount it. You need to be able to remove the wire, so dont make i too hard to undo. You will probably struggle a bit here for the first couple times, but its the only difficult part.

I like the OEM seals. mainly because I have had bad luck with seals in the past, but now, since going OEM, they last alot longer. got that tip from a local suspension guy. Its not worth getting cheap seals, or old ones, if they dont last all season. I think dirt that has dried to the fork leg or that has found its way past the dust seal is the major culprit in fork seals leaking. That was pointed out to me by a few smart guys here on kxriders. Otherwise, the alignment bushings need replaced also, if there is a chronic problem leaker.

I like 5wt-7wt oil for play bikes. I tried 10, but it was way too stiff for me. Sorry for the book, I have just recently been doing the seals myself and also struggled to get any info. Great advice, from guys on here on every topic, but not enough to understand it until I worked through it a few times with my manual. I have done about 10 forks, so take the info for what its worth. Please feel free to add to or critique my method, It would be good info to have for everyone. It costs me about 50 per side, for someone else to do the job and roughly half that doing myself, so its worth learning.
« Last Edit: April 20, 2012, 03:47:24 PM by Hillclimb#42 »

Offline alward25

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Re: changing fork seals...
« Reply #12 on: April 20, 2012, 12:27:44 PM »
Great write up!  Just need a play by play with photos!!!  I know, we can never be satisfied.

Thanks!!
Alex
"Let there be light"

Offline turdle

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Re: changing fork seals...
« Reply #13 on: April 21, 2012, 01:45:10 AM »
Great write up!  Just need a play by play with photos!!!  I know, we can never be satisfied.

Thanks!!
Alex
X2  :-) if you could post pics next time you do a pair, that would be awesome

Offline andydunne

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Re: changing fork seals...
« Reply #14 on: April 21, 2012, 01:52:02 AM »
Holy sh#t that is a great write up Hillclimb, my balls are getting bigger by the minute for this job :lol:
Thanks very much for the advice on the seal too, Oem it is so :-)