Hello all, i have a b7200 kubota with a tiller attachment on rear and a blade on the front. Last week i was gonna start tilling my gardens here and the 3 pt hitch wont lift. the front blade hydraulics work just fine with no issues but not the back. If i unhook the tiller and put hand pressure on it lifts slowly but just wont with weight. So far i have removed and cleaned hydraulic screen and changed hydraulic oil but its still doing same thing. Could it be a stuck valve somewhere or something? very new to this tractor so Any help would be very much appreciated!! Thanks guys