Hello. I own a Massey Ferguson 50 high arch row crop. My Dad bought it 30 years ago and has been used every year that we've had it to put in hay. I rebuilt the motor about 10 years ago and other than a steering issue I've never had any trouble with the tractor. Until now. The other day I started it up to go put a bale of hay in and when I walked away from it I heard a loud boom. I found the lift arms came up and it split the top housing cover under the seat. It split it between the 4 nuts that have studs coming up through the housing. I haven't taken it apart yet because I've never been inside this part of the tractor and I'm reading as much as I can and gaining as much info as I can on how to fix it. I have read it's either a faulty relief valve and or out of adjustment. The relief valve should be no problem but I can't find anything on how to adjust it so it doesn't happen again. I can buy a new bare housing for 300. How hard is it to take the guts out of one and put in the new one? Thanks for any help I can get.