Went and got everything today for the 50 hr service and when I told the guy to give me SUDT at the service desk, he said that i did not have a need to change the hydro fluid until 150 hours as that is what they do at the shop and they are one of the largest Kubota dealers in the US. I have read here on the forum to change it at the 50 hr service mark. So should I change it or not? He said If I used it hard every day then maybe i could but since I have had it over a year and only have 50 hrs on it, I should not worry about it.