KDXRIDER.NET

Hey everybody! I've been fighting with the proper way to refill the KDX rear shock with oil as the resevoir doesnt seem to come apart so I can refill with oil without air in the system ('86 model) I was wondering if anyone knows if I can just go buy a different resevoir (rebuildable) and fit it to the KDX shock cylinder? I still have the bolt to bind them together and I just wondered if it would work.
Thanks folks!

Yes you can swap reservoirs. I have done so on an old Suzuki that had a damaged canister/hose. Replaced it with a similar canister and had a hose made at a hydraulic shop.

But I'm having a hard time believing that it won't come apart. Haven't ever seen any remote reservoir KYB/Showa made that way, and I can't fathom how they would even put it together at the factory.

They do come apart - push in the end to expose the circlip, remove it,clean up the gunk and pull the bladder out.

I guess I'll give that a shot, I'm just worried that the 20+ years of corrosion is gonna make it seem like a weld and nearly impossible to take apart, But, I guess Ill have to give it a shot. Any suggestions on how to start with this severe corrosion? To get the head seal down to expose the snap rings I had to rig up something to not hit the shaft and hit it with a hammer, just to get it to move! then the snap rings inside had basically fused themself into the cylinder. I hate it when no one maintains stuff :/ but hey, I guess thats why I bought it, a project haha

On mine I used a vice to compress the end with a socket. Once compressed, with the circlip out, I used a brake cylinder hone to clean up the surface before I attempted to remove the bladder, but you could use sand paper, etc. to do the same thing. If yours is really too corroded, you can get rear shocks for these bike on ebay pretty cheap, if you're patient - most sellers will take an offer.

Well currently I'm in college for a diesel tech and were in the shop everyday so specialty tools and help isnt hard to find, I could be able to get it done. What end will compress? the side with the schrader valve? I'm picturing a socket on each end to support it with the vice so they are even and then crank it down. I'm just trying to gather as much info as I can, as I can see myself putting it in the vice and having the bottom (part with the line to the shock body) going in and freaking out. From what I know the top should move in right? and once its out a good clean should do the trick and make reinstallation easier. Am I on the right path?
I really appreciate your input.

The shrader valve end is the movable end (cap) - as a matter-of-fact race tech sells a replacement cap and the bladder for this shock - but I wouldn't replace anything unless it's shot. I pulled apart three shocks from the mid-eighties KDX's and all the bladders were still good - but if you need a replacement race tech has it. The main thing is to clean the air/elements-exposed end of the cylinder as much as you can before you pull the cap/bladder out so they aren't damaged in transit by the rough surface.

Thanks for the info KG,will be a help when I get to the one on my 86 as well.Unlike Noob's I can tell it's 2 pieces.Hitting the bolts and cap with penetrating oil now so it should be easier when the time comes to get it apart.

Just for reference, this is the exact resevoir I have http://www.ebay.ca/itm/1985-Kawasaki-KD ... 70&vxp=mtr

Damn thing looks solid.
this is correct right? and can be dissasembled?

That is for an 85 or older - I wonder if you have an 85 bike or someone put an 85 rear shock on your bike? That does not look like it can be disassembled.

Thats what I'm thinking! Been thouroughly examining it and it looks pretty solid, and no matter where I look online, I can not find a definite answer or guide as to if I can pull it apart, I'm stumped and Don't really wanna go buy a whole new system. Im wondering if there is a way to properly recharge it without opening it or if I'm screwed.

Here's what a 86 res looks like;


Not the same as the one in the eBay link for sure.

deffinatly opposite, this bike I got was a crap shoot, but hey, for $100 and a little bit of work I got in running and picked up a spare motor ('86) for another $100, the '86 motor is powervalved and I just finished rebuilding it and its ready to be installed and now the suspension is the problem area. Not quite sure what I'm gonna do.
I ran the vin and it is indeed a 1985. Gonna be alot of fun when its done, just gotta get this sorted out.
Any and all input is much appreciated.

KDXnoob1 wrote:Thats what I'm thinking! Been thouroughly examining it and it looks pretty solid, and no matter where I look online, I can not find a definite answer or guide as to if I can pull it apart, I'm stumped and Don't really wanna go buy a whole new system. Im wondering if there is a way to properly recharge it without opening it or if I'm screwed.

Nah, if the bladder is still good, the real issue is getting all the air out... so you want to make sure the reservoir is full of bubble-free oil. Pull the line off, drain out the old oil , fill with new oil, connection port up, give it time for any bubbles to surface (gently tap the body with a plastic hammer) then connect the line, then fill it with oil - same process.
Connect the shock body up... then put about 35 lbs of air in the reservoir...this will help purge out any residual air bubbles in the reservoir.

Add oil into the shock body until it's about 3/4 inch from the top, put the shock shaft in SLOWLY, push the shaft up and down several times slowly making sure you don't come up too high and draw in air.... it should feel smooth after several cycles - with no "skips" from air pockets.

Now, with the shaft in it's fully extended (but still sealed) position, release the air in the reservoir.. you should feel the shock shaft go in slightly and be able to expose the circlip recess. Install the circlip (make sure it is seated).

Fill the reservoir with about 90 lbs of compressed air - and test the action of the shock, it should be smooth both ways and return to full length on its own.

Bleed out the air and fill with nitrogen - I'd recommend about 140 psi for this older unit.

Damn gumby! I never even considered that! Thats awesome! Sounds like it'll totally work and ill give that a shot, thanks so much man! Will update on progress! Will have to wait till after the weekend to get access to a vice as the line is connected pretty tight and I cant get a wrench on and hold the resevoir with enough force to open the connection. Thats what your implying right? Undo the connection, dont just yank the line eh?
Haha, thanks! Will update as it progresses!

We had an old Honda MR175 back in the day that had a reservoir similar. If I remember the end cap unscrewed instead of being held by a circlip and you used the nut at the base of the schraeder valve to remove it...but damn that was a long time ago

Check out this on Thumper Talk, maybe it will help you with the shock: http://www.thumpertalk.com/topic/886803 ... 0-rebuild/

At least there is a picture that you could use as a reference.

Hey all! The shock is done, I took your advice gumby and did everything you said, worked flawlessly! Thanks so much! Just gotta get a nitrogen charge and its gonna be all done!
Thanks all!
Special thanks to kawagumby for the instructions and for imparting his wisdom on me!

You are welcome...glad to help in rebuilding these great bikes!