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Rear suspension Nitrogen/Air - Empty works?

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My rear suspension is CRAP.. not plush at all, infact not even the settings (low/high rebound) work anymore it seems. Seems like the shocks are non existant, only the spring works. The problem is that I don't have any gas on the gas can.. can that be it? Wasn't fun to race like that. I reckon that could even damage the suspension.

If I don't have nitrogen and if really necessary to fill the cardridge, can I just use air instead? Not sure if I will find Nitrogen here (Kenya).

Any tips to refil it? heard if you don't take care when loading it you can blow out the thing.

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the seal head is forced to the outside by the nitrogene. if you have no pressure, the shock will leak after a short time. now your oil is gone and you need a rebuild.

air can be used though nitrogene is recommended

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don't just pressurise it, it needs a rebuild by the sounds of it

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Also if you do not pressurize it then you will have tons of cavitation. The pressure in the bladder stops this

theDogger

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Ouch.. one more expensive exercise.......

Any way to make sure I need a rebuild?

In case I need it, is that something I could do here by myself?

Over here in Africa we dont have many experts on suspension. I just did a whole rebuild, so assume that wouldn't be such a big pain to dig into the suspension.

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Any way to make sure I need a rebuild?

you wrote:

"Seems like the shocks are non existant, only the spring works."

no damping - no oil...

so you probably need a new seal head and shock oil. do a search here for shock rebuild and decide if you have the skills to do that...

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Guys, before I tear it down, I have one more question:

- Is it possible that the settings adjustment doesn't make a difference simply because I have NO air/Nitrogen on the compartment? I checked now and is completely empty.

I'm asking because it was working just fine, there was no sign that it leaked or so, so I find pretty impossible for it to have lost the oil....

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no nitrogen will make it act weird , get it gassed and see if it functions normally

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FWIW I find when the bladder pressure gets low, air makes its way into the shock so yours is likely full of a frothy mess rather than just oil. pressurizing it will help but it won't restore "normal" function if there is a lot of air in the oil.

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FWIW I find when the bladder pressure gets low, air makes its way into the shock so yours is likely full of a frothy mess rather than just oil. pressurizing it will help but it won't restore "normal" function if there is a lot of air in the oil.

+1 :thumbsup:

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Thanks!

In case that happened, any way to get the air out? If I leave it quiet will it "drift"out of the oil?

If the shock is depressurized from the bladder, you could top off the fluid

through the comp. port. Even if when the bladder is depressurized you will have a good burst of air when you crack open the comp. port so becareful.

Have rags ready to help capture the fluid.

Even if it does drift out of the oil you still have air in the shock.

To get the air out you would have to do basically a rebuild or "top off".

james

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Guys, before I tear it down, I have one more question:

- Is it possible that the settings adjustment doesn't make a difference simply because I have NO air/Nitrogen on the compartment? I checked now and is completely empty.

I'm asking because it was working just fine, there was no sign that it leaked or so, so I find pretty impossible for it to have lost the oil....

one word of advice, dont go constantly checking the pressure back there. the bladder is so small that one check here and you lose 30psi, another check and you lose more. its not like a car tire where that little you lose makes no difference since the tire has so much space inside.

go get it charged and check the function, but dont get trying to measure it with a gauge IMO.

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You need the pressure in the bladder to stop cavitation!!!! There is no getting around it. You need to take the shock apart and see what is going on. Is the bladder bad itself or did your buddy let you nitro out. Either way with the air that you have in there you will have no dampening with no nitro. Check this video out to see what I mean

@ 3:30 you can see cavitation with no pressure and what pressure does for cavitation..

Here is another video with a close up

theDogger

theDogger

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You need the pressure in the bladder to stop cavitation!!!! There is no getting around it. You need to take the shock apart and see what is going on. Is the bladder bad itself or did your buddy let you nitro out. Either way with the air that you have in there you will have no dampening with no nitro. Check this video out to see what I mean

@ 3:30 you can see cavitation with no pressure and what pressure does for cavitation..

Here is another video with a close up

theDogger

while most of us may have known this, its always impressive to see it :thumbsup:

what the vids do not show is, that on mx shocks the seal head would move up and down when not pressurized

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You need the pressure in the bladder to stop cavitation!!!! There is no getting around it. You need to take the shock apart and see what is going on. Is the bladder bad itself or did your buddy let you nitro out. Either way with the air that you have in there you will have no dampening with no nitro. Check this video out to see what I mean

@ 3:30 you can see cavitation with no pressure and what pressure does for cavitation..

Here is another video with a close up

theDogger

theDogger

Amazing

Couldn't be more educative

Basis the video and the fact that my shock was running without any pressure, for sure cavitation was the problem

In the video it appears that as soon as the pressure is back the functions come back to normal, so I hope it's my case?

I removed the shock and will remove the spring tomorrow and see how it behaves

Tks guys

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In the video it appears that as soon as the pressure is back the functions come back to normal, so I hope it's my case?

like bushmechanic said, when the bladder pressure gets low, air makes its way into the shock. you create a vacuum while compressing the piston rod. the seal is designed to seal against pressure, not against vacuum

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