KYB suspension help


12 replies to this topic
  • Stayinthirsty

Posted April 01, 2016 - 04:45 AM

#1

While breaking down my forks to replace the seals I ran into a issue that concerned me. 1st fork came apart easy but when I tried taking the bottom rebound nut off trouble followed. When compressing the fork the rebound nut would not come out of the fork leg. It seems to be retracting into the fork leg. I finally got it off and noticed the rod on the inner chamber was retracted in. I can pull it out and it retracts back in everytime. Anybody know whats happening here? I assume it's time to break the inner chamber down and refill it.

  • Sheriff245

Posted April 01, 2016 - 04:47 AM

#2

There could be an air bubble in the inner cartridge. When you try to extend it, the bubble expands, creating a low pressure spot. I would rebuild the cartridge with new seals and inspect all internal parts.

  • grayracer513

Posted April 01, 2016 - 06:30 AM

#3

Nothing to concern yourself over at this point.  The cartridge has managed to partially evacuate itself one way or other and is simply responding that way because of it.  Just go ahead and change the oil in them and bleed them. you'll be fine.

 

Resealing the cartridge and base valve assembly is probably a worthwhile idea here.



  • Stayinthirsty

Posted April 01, 2016 - 07:35 AM

#4

Thanks for the replies. Thankfully the kit I ordered has all the seals and orings for the cartridge and base valve.

  • grayracer513

Posted April 01, 2016 - 08:45 AM

#5

You'll need a tool for the removal of the cartridge rod seal head.



  • TN Dirt Rider

Posted April 01, 2016 - 08:48 AM

#6

You'll need a tool for the removal of the cartridge rod seal head.


+1 it's a pain the butt, even with the tool.

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  • grayracer513

Posted April 01, 2016 - 08:56 AM

#7

Not that bad.  You do need to understand that the cartridge itself has a threaded joint midway up its length that may loosen before the seal head does, and then if that happens, you'll need a precisely sized tube clamp to hold it without crushing or reducing the diameter.  To avoid that problem, hold the seal head tool in a vice while turning the upper octagonal end with the "cap" wrench, and apply heat prudently to the seal head to make sure that it comes off instead of cracking loose the mid-tube joint. 



  • TN Dirt Rider

Posted April 01, 2016 - 09:36 AM

#8

To avoid that problem, hold the seal head tool in a vice while turning the upper octagonal end with the "cap" wrench, and apply heat prudently to the seal head to make sure that it comes off instead of cracking loose the mid-tube joint.


Good idea. I went the route of making a tube clamp and that took a few tries to make it work. Took more heat than I was expecting to break it loose.

  • Stayinthirsty

Posted April 02, 2016 - 01:23 PM

#9

I got the valve out and the white plastic piece is shattered. Any idea where to purchase that at? Can't seem to find it anywhere. Thanks in advance.

  • TN Dirt Rider

Posted April 02, 2016 - 03:46 PM

#10

Search for KYB free piston and you'll find them. When mine broke I replaced them with some Aluminum ones from sdi (I think).

Edited by TN Dirt Rider, April 02, 2016 - 03:47 PM.


  • RockerYZWR

Posted April 02, 2016 - 04:17 PM

#11

Race Tech has them

  • Stayinthirsty

Posted April 02, 2016 - 04:21 PM

#12

Thanks guys! Good to know what to call the "white plastic thing" and where to find it lol

  • grayracer513

Posted April 03, 2016 - 03:55 PM

#13

It is the "free piston" and should either be drilled to vent it, of replaced with the slotted aluminum ones. 

 

Available from Suspension Direct in either form.

 

http://www.thumperta...-kyb-sss-forks/

 

http://api.viglink.c.../YZMODASSEM.htm







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