hi leaky, let go. punch in exmark parker ross service manual. go to pdf uht product series service procedure-exmark. its the complete service manual, its what I use at work. now I see the hydro is out. can you tell its only leaking at bottom seal? should be no play at bottom shaft. seal kit is about 80 bucks, if it has play bottom assembly about 400 bucks. you said its a 2011 model but your pick shows the original oil filter in hydro, it should have been changed at 250 hrs and every 500 hrs after that! no seal at the 2 allen bolts, just the O-rings in the 2 tubes so your ok there. good luck