I am pretty sure the HST relief valve pressure is the same on all 3 CK HST models.
If the CK25 has enough power to open the relief valve then the only difference going to the CK30 is PTO power.
I routinely hit the relief valve on my CK30HST when doing tree shovel work and at times it can be frustrating. On the up side it is teaching me to not treat my tractor like a bulldozer. I should also mention that I only hit the relief valve when I have good traction and when my backhoe is on (I also have filled tires). With the backhoe off I can spin the tires all day long.
If the CK25 has enough power to open the relief valve then the only difference going to the CK30 is PTO power.
I routinely hit the relief valve on my CK30HST when doing tree shovel work and at times it can be frustrating. On the up side it is teaching me to not treat my tractor like a bulldozer. I should also mention that I only hit the relief valve when I have good traction and when my backhoe is on (I also have filled tires). With the backhoe off I can spin the tires all day long.