Rear Mono Shock

**stevenhuot** · #1 10 Apr 2005

Help, riding down in Brazil and after trying 30 times to repair the progressive suspension rear shock (proprietary seals inside not available in SA), I am putting the original new shock from my KLR650 back on. Unfortunately when my friend brought it with him on a visit from the US he had to remove the nitrogen from the air stem (the one under the black plastic pressed on cap) in order to get it on allowed on the plane. As such, he tells me liquid came out, that "in no way" looked like hydraulic fluid instead of just compressed air. Is this possible? Liquid Nitrogen too? I don't believe it but he is insistent.

Anyone have experience with the original recharging and refilling it? What must I do? I assume I am now low on fluid and out of gas. How do I fill it properly and then, what pressure of Nitrogen if I can find a shop to charge it. If I cannot, will it run ok with normal air, air pressure?

Regards. 2.5 years on 2 wheels across all the Americas... but still challenged by this KLR, Steve

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Steve Huot
Currently in Brazil after riding for 2.5 years from NY to get here...

**pantrybear** · #2 13 Apr 2005

The stock charge is 150psi nitrogen and the stock oil is 5W and there should be 130cc's in it.

Check out this link:

http://calgarydualsport.tripod.com/k...procedure.html

Hope that helps.

**stevenhuot** · #3 13 Apr 2005

Thanks so much. That is extremely helpful. One more thing that concerns me though... The shock I have is brand new, never before on a bike. So, why would oil come out the nitrogen valve stem? Aren´t the two things, oil and nitrogen kept seperate? Does this mean the diaphram or whatever one would call it that seperates oil and gas is leaking?

Oh, and is there a way to refill to 130ccs of 5w oil without fully disassembling the shock?

**pantrybear** · #4 13 Apr 2005

I just had my shock rebuilt but had a dealer do it so I'm not intimately familiar with filling oil and nitrogen. But, I think you should just have it refilled with nitrogen and try it out. Depending on how much fluid came out, you probably still have enough to work just fine. If it seems a bit too bouncy, turn up the rebound damper to II or III. If you still think it's bad then you can start trying to figure out how to get more oil in.

Good luck,

Matt

**pantrybear** · #5 13 Apr 2005

One more thing, according to the link above, when the shock is being reassembled, air is bled out of the valve until oil bubbles up so I think oil coming out with the nitrogen makes sense.

**AndyT** · #6 13 Apr 2005

What knowledge I have of shocks comes from sports car racing, so with that disclaimer...

Many low cost, and some high cost, shocks are called emulsion shocks. That means the gas and oil are mixed together, and after the first few strokes (bumps) they are mixed up well enough that the mix is a relativly constant viscosity throughout, and is tolerably consistent for damping purposes, so having oil come out with the gas does not neccessarily mean you have a ruptured diaphram.

The reason you need gas in the first place is that when the shock compresses, the rod enters the fluid chamber and displaces some volume. If there were no compressible gas, the shock would hydraulic lock and either refuse to compress futher, or blow out a seal. For this reason, it is very bad to overfill a shock. If you refill your shock with the recommended amount, make sure you have emptied it completely first. The KLR uses a shrader valve, just like a tire, for it's fill port, and I would think that if you removed the valve core and hung the shock upside down it would drain the oil, although I have not tried this myself.

When nitrogen is not available, I have charged shocks with air. When draining the fluid later it looked like a milkshake, so it does get some moisture into the system, but you can do it in a pinch.

Hope this helps.

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Andy Tiegs
http://www.tiegs.com

**stevenhuot** · #7 13 Apr 2005

This helps a lot. One concern remains, however... Someone else told me that there IS a rubber diaphram in this KLR shock... I have disassembled my after market Progressive Suspension shock over a dozen times;... sadly enough... and that one has a rubber bag in there that would eliminate mixing of the Nitrogen. I assumed the Kawasaki original part was the same way, but oil coming out and your advice makes me think otherwise. Anyone know that for sure, that oil coming out is a normal thing for a new, well functioning shock?

Oh, and could I squirt new oil in the valve stem opening? As long as it is not more than what came out of course... Bouncy in Brazil. Steve