I'm going to start out with an admission of guilt and will hope I don't get flamed for it. I've never attempted to set the pressure (or even check it) in the filled rears of my 2011 2520 turfs until about a week ago. This has led me to the realization that I don't know what the recommended process here would be.
My dealer filled the rear turfs before delivering the machine to me when I bought it in 2011. The wheels are mounted in the narrower stance position which means that the valve stems are on the inner portion of the wheel (not facing outward). The fluid level is well above the highest point that the valve stem ever sits at, so there's no chance of putting a pressure gauge on it in any fashion to check the pressure.
I fired up the compressor and set the output pressure to 22lbs and connected up the air chock. I listened to the fluid inside bubbling away as air was entering the tires, but didn't get to a point where it equalized to a point where it would stop. So, I don't have them up to full pressure and definitely need to "finish the job" but am looking for some guidance as to how to do this the best way.