Bought used John Deere from dealer with 650 hours on it. Got it home drove it off the trailer and about 100 feet later, made loud noise when hydraulics were maxed out. Steering, or three point or FEL. Once that happened there was no hydraulic power until you stopped and restarted the engine. I found that the idler gear that drives the hydraulic pump had slipped towards the rear of the tractor and would disengage when the hydraulic pressure was high. What fun. Now I get to disassemble about half of the tractor just to get a snap ring to stay where it belongs. Of course because of its age there is no warranty. I bought the tech manual from John Deere and it is better than nothing, but not very detailed as to this particular issue. Wayne