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DaveU, really like your idea. I've thought about the possibility of rebuilding these shocks because I'm a farm boy and in my life anything is rebuild-able. I'm not a machinist but I have a cousin who is and has done some incredible stuff. I was going to ask him about it some time. 3s's are rare around here so I have a real hard time trying to find old ECS struts anywhere. Good luck, hope you can make something work.
I'm an IT guy, but also a farm boy.. just small scale, some beef, some chickens.. but yup.. use it up till it's wore out.. then weld some stuff to it to make it go even longer.. :)

I'm no machinist either.. but it's amazing what you can accomplish with a grinder, a press and a welder.

The trick will be the seals.. has anyone measured the shaft and body diameters front and rear?

i'm hoping there is some off-the-shelf pieces we can re-purpose to seal the body to the shaft.

Hoping to be able to get some worn out units to work on this winter.. see if i can't make something work.
 

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Went ahead and put the fitting there, what it came out was something like water and kinda looked like Jack oil, refilled and pumped the shock until no more bubbles appeared on the bottle (can't see there but the hose is attached to a jack oil bottle with the pointy end sealing that hose), now it has resistance to compress and extend, still goes up slowly, that is the nitrogen issue right..? Got a bunch of these to test stuff..
 

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I love your work Alberto!!!

Can someone please at least partially translate some of what he is saying in his video?

I am (and will) continue to follow this...

Bob. :)
 

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Also interested in this, been reading about the Struts for a while, ECS are no longer in production and a pain in the ass to find nowadays... Posts from 2004 already stating that the KYB GR2 is not a really good strut, that it doesn't last, too harsh, and other things that I can't recall.

Just being able to "rebuild" the ECS strut, changing the oil (Study what oil to use, how much oil), changing the seals (name/number) pressurising it again (pressure value), even inspecting the mechanism that changes strut mode, would be a massive improvement since I've not found a single "strut rebuild" post.

Saw someone machining the Stock strut housing to fit a Bilstein, also saw Ralliart3000GT with some kind of contraption with the Stock struts with adjustable height with Bilstein shocks, but couldn't find any OEM strut rebuild's.

Youtube username RecceDG did a great video (
) explaining how the whole strut works, for what I can see in the video, it's just a twin tube shock, with a clever design in the valve body. I know he posted something in this forum, but I can't find it right now.

The video that Albert0 posted above, where a Russian guy explains how to do a rebuild is exactly what I was expecting to find, but couldn't find any 3S that has done it. The Russian dude removes the crimp in the strut and replaces with a nut, making it even easier for a future maintenance

This is what Ralliart3000GT came up with back in... 2003-2004 (I think), one of the first posts in this forum is this suspension being advertised.

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This is from another user, that I won't remember the name, he removed every component from the stock strut and machined the original housing to insert a Bilstein strut.

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I was scrapping all the extra stuff that I had from repairs and it reminded me about the ECS rebuild, popped the cover and I was searching for a replacement seal, can't find any cross reference for this seal: NOK BR4452E.

Is there something special about shock seals (in case that I start search just by size)?
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bumping!!

Any updates??
 

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Reached out to KYB technical support for some help and guidance.
 

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Most likely a special NOK reciprocating seal. Reach out to NOK for information and a refreshed part #.

Here is a "How it is made" video on shocks

Some technical details behind gas charged twin cylinder shock absorbers


For rebuilding I see a few things on the to-do list on those serious on undertaking this.

1) Dust Cap Puller
2) Custom Tool to De-Crimp Double Lip End Seal - Residing pressure needs to be considered in the design of this.
3) Shock Oil (unless KYB provide you with the factory specifications, good luck here) Maybe if you are clever you can buy the appropriate hydraulic ASTM standard test tools to determine the proper properties for the oil. You can buy new KYB struts (without ECS) and measure their fluid properties. You may not even have to go this route if you can ensure that the strut hasn't leaked oil and only nitrogen. Not my area so do your research.
4) Special crimp tool to recrimp original tabs with press
5) New friction fit dust cap
6) Recharge reserve chamber with nitrogen gas (you need to find out what pressure of nitrogen is required)
7) Either servicable recharge port need to be welded in or method to charge and weld nitrogen gas safely

This of course gets much more complicated if anything has failed electronically inside.
 
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another option instead of pressurizing with gaseous nitrogen is to pressurize with liquid nitrogen. This forgoes the need to figure out how to seal the tube after pressurizing with nitrogen.

I could do the research to calculate how much liquid nitrogen would be needed if anyone here is serious about rebuilding these.
 

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Reached out to the NOK partnership in the USA. I'll let you know if I hear back on the seal type and size, which will allow to find cross references if original is hard to get
 
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Heard back from KYB shock absorbers. They were contracted to build these for Mitsubishi at the time. Only ever offered through that channel (dealer) as it was Mitsubishi's original design.
I asked if technical drawings can be made available and explained what we are trying to achieve. Asked for details on proper nitrogen pressurization and dampening fluid properties.
 
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Direct from KYB. You're welcome ;)
Now you have a head-start at least.

Sorry, we cannot share any drawings or oil specifications as it is Mitsubishi’s proprietary information. I can however tell you that the nitrogen should be charged to approximately 150 psi. Sorry I cannot share much more information than that.
 

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Liquid-to-gas expansion ratio of nitrogen is 1:694 at 20 °C (68 °F)

To derive pressure one would have to know the approximate volume of unoccupied space.
As a reminder, oil is not compressible.
 

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I was actually lucky enough to get the very last brand new front ECS strut available in the country for my '94 VR-4 a few months back. I then found a JDM pair on Ebay and purchased those just in case but I couldn't agree more that something needs to be done or some solution found in order to keep our vehicles running as they were intended to. Does anyone know if in fact it definitively was KYB who manufactured the ECS struts? If so, I'd be more than happy and willing to reach out to them and see what if anything they know or can do or whatever so long as it's helpful.
If you are able to contact them why not do so to first ask them whether or not they were the manufacturers of the ECS strut assembly?
 

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If you are able to contact them why not do so to first ask them whether or not they were the manufacturers of the ECS strut assembly?
Sorry my apologies..I didn't read to the end of the entire thread to see youd already done that. I really hope we can all bring this ECS project to fruition
 

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Well done so far!
If enough people sign up, surely we should be able to find a reputable company to custom make a batch?
Do we know when Mitsubishi stopped their production?
 

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Wow, that's some research, so basically everything is top secret protected by intellectual property, I've read some articles from bilstein, kyb, monroe, etc. and they mention that low pressure nitrogen is introduced to the strut and most of them use liquid nitrogen, but the kyb guy says that 150psi, but low pressure liquid nitrogen makes sense now.
 
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