Tractor Repair: MF 50 hydraulic issue, bush hog, brush hog

Question
I own some acreage which needs to be brush hogged a couple of times a year.  My MF 50 has a hydraulic issue.  It won't keep the brush hog raised.  I will raise it and within about a minute, the blades are on the ground again.  It raises fine to go over a stump or rock but goes right back down to ground again.  I like to keep it about 2 to 3 inches above dirt level.

Thanks.

Answer
First, check your hydraulic system completely. Check the fluid level, check the fittings for any leaks, etc. What this sounds like, though, is a faulty internal seal which is allowing leak-back, OR, a faulty seal in a ram cylinder. You haven't specified whether you are using a bush hog configured for a 3 point hitch or drawbar.....You may, as well, have a plugged hydraulic filter, which would account for the pressure problem.