WER Fluid change

ATF works fine.  You might want to run your adjuster a little further out to account for the heavier oil. 

After you get the old fluid out, an easy way to fill the damper is to immerse it in a small tub of ATF and activate the arm until all the bubbles come out.  It's a little messy but it is much easier and faster than dripping the fluid into the hole with a squeeze bottle. 

 

Don't "drip" the oil into the hole; use the squeze bottle and force the oil into the unit. Takes all of 5 seconds.

Hope this helps.

If you change it yearly when it isn't so dirty just suck it out with a syringe. Then fill it with the syringe and 7 wt fork oil works good. You can run the adjustment screw 1 and a half turns out.