I installed the hydraulic pump yesterday to find that one of the bolts would not tighten. I figured another stripped threads that I needed to repair. I remove the pump today to get started on the thread repair to only find the sides of the bolt hole gone in that area. My guess is that it cracked when something hit the bottom of the pump; which was repaired by someone; perhaps Dad. I will probably find the pieces in the bottom of the bucket of hydraulic oil that I drained from the tractor. The only thing I know to do is to try and use a slightly longer bolt; I did measure to see, and don't get too heavy-handed with the torquing. This is not something I am going to be able to repair.