Tractor Repair: Kubota tractor Model BX2200, diesel tractor, loader model

Question
I have a 2002 Kubota diesel tractor model BX2200 with a front loader model LA211. This past weekend we went down to the farm to do some work. The grass needed cutting so I took off the bucket & unhooked the hydralic lines on the tractor with the help of a neighbor farmer.  I was into about 30 min. of mowing when the tractor started smoking a little under the seat. Okay I thought maybe a mouse had built a nest and the grass and whatever was getting hot. I turned the tractor off, cleaned out any grass and started mowing again. 15 min. later it was doing it again and put the tractor back in the barn. Where you put the hydraulic oil in in the back, the cap melted off. I had filled the hydraulic tank prior to originally running the tractor as a couple of the hydraulic lines were already leaking a little bit-that is why I wanted to take the bucket off. The farmer came back to check what what wrong and noticed that he did not hook the one hydraulic line back into the other one. Does that mean there was no hydraulic oil flowing???? Now the tractor won't even start. I hear the clicking of the glow plug, but when you turn the key to start there is nothing.  Is my diesel engine fried? Is it the hydraulic pump?  This little tractor has been great as it has many hours on it since we bought it new. Would like to hear what you have to recommend.

Answer
  Hello,

  Very interesting story.  Unfortunate, but interesting.  But I'm happy to tell you that your engine is not fried.  Because the hoses were not connected, it sounds like the hydraulics were deadheaded while you were mowing, which over a period of time causes the hydraulic oil to overheat.  So while that has nothing to do with the engine, you may still have some damage to the hydraulic system.  The hydraulic pump was building pressure, but the oil had nowhere to go, so the pump is probably toasted.  The pump may be seized up so the engine can't turn, or it may be a coincidental electrical starting problem that is not related to this incident.  Besides the relay clicking, you should also hear the starter click when you turn the key to start position.  Besides the pump, there may be some other plastic parts or rubber seals that have been damaged by the extreme heat.  Have the entire hydraulic system inspected by a dealer or other repair shop.  If it got hot enough to melt the filler cap, that's serious enough to do some damage.  If this is a hydrostatic drive machine, it could be very expensive if anything in the hydro was damaged.

 I hope things go well for you,

                  Arnie