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Is there a front fork seal kit? Not sure what I'm looking for?

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06 May 2021 21:09 #848131 by Shdwdrgn
Hey folks, warming up the bike again for the year, but I think it's time to finally tackle the oil leak in the front forks.  I have an '81 KZ1000J, but it looks like forks from an LTD or CSR (the axle mount is on the front of the fork, not the bottom).  I've had the forks completely apart once to fully clean them when I got the bike and I didn't notice any unusual wear at the time, but that's not to say I know what constitutes 'unusual' for this assembly. :)  Basically what I'm seeing is continual oil seepage from the top of the lower tubes any time I ride and the air pressure leaks out (a lot, but not completely) over the Winter.

So I know there are rebuild kits for pretty much every assembly on the bike, but apparently for the forks it's not actually *called* a rebuild kit?  I tried looking on Partzilla but I only saw individual seals, no kits.  I really don't know what I should be replacing to get the forks sealed up again so I'm hoping someone could be kind enough to point me in the right direction?  Thanks!

1981 KZ1000-JK1
She's a beautiful mess, and I've made her all mine

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07 May 2021 04:37 #848136 by 73z1
Fork seals only last a few years then they leak.
Buy new seals.
 

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07 May 2021 06:43 - 07 May 2021 06:50 #848143 by martin_csr
You normally buy the stuff separately.  Seals usually come in pairs, but I'm not sure how Kawasaki seals are sold.  Dust boots may be needed as well.  Also, old old snap rings can be brittle, so you might need those too.  OEM is preferable, but I installed K&L fork seals over 7 yrs ago with no problems >> made in Japan & identical to oem.  I also installed the dust boots but I don't recall if they were K&L. I forget.  I've never had a problem with the brand.  FYI, fork seal life is probably dependent upon the mileage & typical road conditions >> some guys ride every day and some places are more dusty & gritty than others.

Just in case.  sometimes a bit of crud or grit can get stuck between the seal & fork tube, so you could try cleaning around the seal.  I think they even sell a plastic flex tool for this, but I would probably try a piece of milk jug plastic & slip it under the seal to wipe away any debris.  If it doesn't work & the seal still leaks, nothing lost.  

 
Last edit: 07 May 2021 06:50 by martin_csr.

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07 May 2021 07:32 #848152 by Shdwdrgn
As much as this leaks, I have my doubts that it's only a bit of crud.  It honestly wouldn't surprise me if the original parts were still in there so it's probably best to just start replacing things.  So if I'm reading everything correctly, I just need to get the pair of oil seals and possibly the snap rings?  I expected it to be more complicated than that.  Is there any trick to getting the tubes separated?

1981 KZ1000-JK1
She's a beautiful mess, and I've made her all mine

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07 May 2021 07:50 - 07 May 2021 08:05 #848154 by martin_csr
Are the bottom allen bolts stuck?  Some guys use an air impact gun. or electric.  Otherwise, you may need to use a inner cylinder holder tool.  Use a brake caliper or hardened allen socket. a cheap allen tool might twist or break, possibly damaging the bolt heads.  

Fork seals.  You'll need to identify the forks first.   From the diagrams at Partzilla the 1000K Ltd & 1000M CSR fork seals are different.  I don't know if they're interchangeable.  They use the same dust boots.  
Last edit: 07 May 2021 08:05 by martin_csr.

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  • SWest
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07 May 2021 08:12 #848156 by SWest

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07 May 2021 08:18 #848157 by Shdwdrgn
Oh yeah I see what you mean.  I pulled up the parts diagram for the CSR from the Kaw site, that's definitely not right either (for some reason I was thinking the CSR and LTD had the same forks).  So I went ahead and ordered the seals that fit the LTD forks, but of course there's no telling if these are even the same year as the bike.  I love frankensteins... 

Regarding the bottom allen bolts, I'm not sure what you're referring to.  When I took the forks apart the first time I didn't pull the tubes apart, I only pulled out the springs and stuff to flush out the tubes and clean the pieces that came out, so the tubes haven't actually been apart before.  I just wasn't sure if it would be fairly obvious how to drop off the lower tubes.  I'm not even certain if I need to remove the entire assembly from the bike, or if I can just drop the lower tubes?

1981 KZ1000-JK1
She's a beautiful mess, and I've made her all mine

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07 May 2021 08:33 - 07 May 2021 08:34 #848158 by martin_csr
I take the forks apart to change the seals, so the bottom allen bolts have to be removed.
Maybe ??? the seals can be pulled without doing so, but I'd rather not risk damaging the upper fork tubes.
And I prefer to thoroughly clean out the innards.  old fork oil can be pretty bad.
Last edit: 07 May 2021 08:34 by martin_csr.

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  • SWest
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07 May 2021 08:36 #848159 by SWest
I have vids of it in my tread. In my case the lowers were 46 years old and shot. Not saying yours are but if you replace the seals and they leak chances they are. Some are easier to break down than others. 
Steve

kzrider.com/forum/13-bike-related/597654...aw?start=1104#848149

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07 May 2021 08:48 #848160 by Shdwdrgn
@SWest - Thanks for the link, but as I mentioned I do NOT have the original J forks on this bike, so those won't fit.

@martin_csr - Yeah when I originally took the springs our they were covered in an ugly sludge.  I used brake cleaner to flush everything out, then rinsed with some fresh oil and dumped that out before refilling.  I had to pop the tops to add more oil last year, so I checked the springs at the time and everything still looked nice and clean then.

I checked the parts diagram again, and I think I see the allen bolt you're referring to (literally under the bottom of the tube).  So I just take those out and the lower tubes should drop off?  Sounds like I should be able to put the bike up on the center stand and pull the wheel?  (oh crap, I still need to mount the center stand back on the bike again!)

1981 KZ1000-JK1
She's a beautiful mess, and I've made her all mine

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  • SWest
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  • 10 22 2014
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07 May 2021 09:18 #848162 by SWest
So you know what forks they are? Lots of listing for All Balls seals on eBay. I don't use any others and NOS is a crap shoot for 40 year old parts. Some come apart easy and some don't. Had trouble with KZ 750G forks. Needed a special tool for that so I didn't take them apart. They didn't leak so I left them alone. 
Steve

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07 May 2021 10:00 #848164 by Shdwdrgn
Well they 'look' identical to the LTD forks (specifically in the axle mounts), and they were mounted to the original head without any modifications so I assume they're most likely from an 81-82-83 model, but I can't really assume anything.  I got the bike cheap because previous owner assembled the starter clutch incorrectly and destroyed the engine housing, so I didn't really trust anything on the bike.  Even though the geometry is a little different, they ride smooth in town and on the highway, so I never worried about replacing the existing forks.

I also saw all the NOS seals on ebay, and agree that for seals I just wasn't willing to trust something that old.  The Amazon order I put in was for some new S&L brand seals, but if they don't hold up I'll order some All Balls next time (that's what I used for all the bearings, and haven't had any issues with their brand).

1981 KZ1000-JK1
She's a beautiful mess, and I've made her all mine

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