Changing fluid in leveling jacks?

JerryofWV wrote:
I was reading the manual for my Power Gear jacks and noticed they recommend changing the fluid every 2 years.

I don't know anyone who has changed their fluid ever, much less every 24 months.

Does anyone change the fluid? Is it really necessary?

I have no plans to do so and other than adding and draining a little from an overfill, it might have never been done since built. Having said that, the rig does have one new jack, so hard to tell when that was replaced, since we did buy it used, back in 07.