Various Kioti members have had to replace theirs. My CK30hst, similar to the CT230, originally came with steel lines to the cooler and the cooler leaked under warranty. The fix was a new cooler and the steel lines were replaced with rubber hose lines. It seemed to last a little longer but then out of warranty, the second cooler started to leak. I bought another cooler and read posts where members were rubber mounting them with good results. I took the new cooler and drilled out the mounting holes so I could place rubber gromments in the two holes. I then cut two sections of 1/4" steel tubing that would fit inside the grommets and over the mounting studs. When remounting, the nuts tighten against the steel tubing and don't compress the grommets. You can grab my cooler and actually move it a little. It's been over 200 hours without a problem compared to the 100 hours or so the other coolers lasted with the hard mounting.
I had looked at a CT230 a year ago and that particular cooler looked different than mine. My cooler has passages like a car radiator that are thin and wide. The CT230 cooler had round tubes which I thought the wall of the tubes might be thicker and handle the vibration better. Either way, I'd still rubber mount the cooler.