I pretty much live on this page on the KS website.
http://kssuspension.com/support/tech-info/
All the parts diagrams, dimensions and service vids per model.
The trick with all droppers in maintenance ... the Etens being steel carts need just that little bit more awareness of how much water is touching the post. Water affects a couple of things in a couple of ways
i) Standing water.
After a particularly sloppy ride, or over zealous wash down water will defeat the Seal Wiper (which isn't a seal), flush out your lube, defeat th DU, get trapped in the roller bearing and then likely sit in your mast for a surprisingly long time. So even if you are out in the desert in drought conditions ... but you spray your post during a bike wash ... that water is likely going to stay in your mast for several days if not weeks.
If you don't use your bike for a few days - say your a weekend warrior ... what happens is the water in the roller bearing starts reacting with the copper rods, the stanchion coat on your cartridge. You have a few different metals here so not you get galvanic currents, facilitated by the water ... yep corrosion usually see as scoring marks on your stanchion under the seal collar ... or at the top of its travel if you left your saddle down.
Add a carbon frame into the material mix and all this accelerates with the added fun of having your post fused into your frame seatube.
The other thing that happens, particularly in hot weather is that the standing water trapped in the mast, boils during the day, condenses at night and cycles over and over until it can escape. Frequent rides helps get this trapped moisture out ... but leave it in there for a while and yep more corrosion this time in the pushrod well deep inside the cartridge ... what this does is corrode the actuator button deep in the cart and jams is open or shut so you either have a post that won't lock into position or is locked solid and can't compress.
This can happen with all posts that use guide rods, internal pushrods ... which I believe is most of the common post brands, not just KS ... but Eten, Cruxi, E30i (found on treks) LEV Si, with steel components are a little more susceptible to rust over time
ii) Water mixed with Mud
Mud helps to accelerate the above in point i)
But what mud does to posts that use a DU bushing like KS is that the water separates out the grains in the mud ... allowing it to defeat the wiper, and get into the DU both at the top and bottom and on the stanchion and into the roller bearing rods. Its now sand paper.
Again it help accelerate i) above as it sands way the stanchion coat exposing either the alloy or steel of the cart, as well as adding minerals to the mix I guess.
But worse ... the grains start wearing down the protective coat of the Teflon used in the DU ... add more water and it acts like a sponge ... making the teflon swell so that it adds to the stiction in the system rather than make it slick. Relubing helps extend the lift of the DU ... but over time, the stiction gets worst, and the cart becomes over worked ... with older models the base plate of the cart can unwind itself as there is torque created in the system as the thing tries to rise and defeat all that extra friction.
Oil leak, loss of air, slower than usual return speed, can't get its full travel without some help (then when you pull it up, air is sucked in and you get the dreaded compression or Sponge Bob)
All of the above can be avoid with user awareness
i) water sucks ... not saying dont ride wet trails, but the more water the post gets exposed to ... the more often you need to service the post.
The more regularly you lube the post, the more protection you give its components, the longer the service intervals. But the more water, the more likely your lube gets flushed out etc etc.
- The natural answer is use a thicker lube ... nope, if you use too thick a lube or one that isn't viscous enough anyway ... you create other problems.
ii) Dont wash your post, keep your hose away from it ... just wipe it down, give it a quick 5 min lube job under the seal collar and store it extended
- extended means any corrosion on the stanchion will be under the DU bushing and has a lesser effect on the performance of the post. But also there is less air pressure in the cart when extended so over long periods of storage or inactivity, air is less likely to escape or migrate to the wrong places and create sponge bob again.
All sounds like too much effort ?
- 5min relube after wet rides and once a month in dry conditions
- 30 to 45min service process if you have access to a nice workstand, workbench with vice and soft jaws. The critical tool is a soft jaw to hold the inner cartridge shaft 8mm dia for Steel carts and 27.2 alloy ones, or 10mm for all the the alloy carts.
The good news for Eten etc is the inner shafter is harder to scratch and the actuation assembly at the bottom of the post is easier to unscrew. if you can get that off its a really easy post to service and clean, particularly with a blow gun / air compressor.
Here is the vid for the Eteni . Cruxi
https://www.youtube.com/watch?v=WJHZX_Fb-0w
soz for the novel