This is to fix the sagging saddle and the pulling out when lifting. I do it this way because it's quick and because I damaged a post before taking off the actuator assembly (cable lever assembly on the bottom) before.
Please proceed at your own risk. There can be pressure in the post causing injury- KS does not recommend to do this yourself.
Please have a look here for the instruction of a complete rebuild:
If you've got a KS LEV that has started sinking, this should fix it. I started this thread quite a while ago and used feedback to improve on it. The process seems to consistently work based on feedback I've received. Just the simple process of recharging the system resolves the issue that...
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Tools, and oil:
5W fork oil
Slickoleum or similar grease
Snap ring pliers
Adjustable wrench
1. Take the post off the bike, pull the cable housing up and sideways to remove, move cable to 90 degree angle and pull barrel nut out.
2. Remove seat, and let air out of post. Screw of the silver actuator assembly with adjustable wrench. Leave it attached to the rod, though.
3. Clamp in bike stand. Put in safety googles. push the post all the way up so you can see the screw with the concentric holes that seals the cartridge. Use Snap Ring Pliers to remove the cartridge screw- (!) careful there is some pressure and oil can squirt out, apparently the rod can spring out, too (never happened to me).
4. Pull the golden rod out, it might help to pull up the cable lever. Pour out all the oil form the post.
5. Here is the trick that allows to do this without further disassembly: There is a small gap between the outside barrel of the post and the cartridge, seal this gap with some Slickoleum or other grease so it does not fill up with oil. Whenever you push down on the post or the golden rod you will need to support the bottom (at saddle holder) with the other hand to not break this seal.
6. Make a collar of paper towels around the post to catch oils spills, this will be messy! Fill the outside and inside tube of cartridge with 5W oil. Don't forget your safety glasses.
7. Insert the golden rod again, pull up the cable lever and circle it up and down a few times- don't forget to support the bottom off the seat post with the other hand. I use a small screw driver through the barrel nut hole, to pull up the cable lever. Make sure the oil level stays up and add more oil as needed, don't pull in air. Leave the golden rod about half way in.
8. Press the cartridge nut down and use the Snap Ring Pliers to screw it back on. Careful- it easily cross threads, if you can only screw it on half a turn it's crossed. When the screw becomes tight, press the golden rod down a bit by pulling up cable lever and screw on some more. Do this 1-3 times till the screw is tight. Remove the remaining oil with a paper towel.
9. Pump up the post to 200-250 psi (or as recommended), screw the actuator mechanism back in and cycle the post a few times. If you got oil between the cartridge and the outer tube put the post all the way up and remove the actuator mechanisms. Put the post right side up and let the oil drip out for about 30 minutes. Done! The post should now be firm again.