My 2615 HST is having problems with sticking brakes and diff lock pedal. The hydro stat works fine. If you press the brake pedal, it will not release the brakes. I have to beat the linkage with a hammer to release. The diff lock pedal is the same way. I have to stand on the pedal to engage and have to pull the pedal up by hand which is difficult. The 3 pt hitch lever is a little stiff but works fine. I have 450 hrs on it and changed the hydraulic fluid every 200 hrs. The only thing in common is the transmission. I知 wondering if this is a transmission issue. No FEL.