My '13 x758 developed a coolant puddle under it one day, so I investigated. As I was checking over the hoses, I found the culprit. A misplaced and loose upper clamp on the lower radiator hose at the thermostat housing was it. However, I also found the head of a bolt on the front of the engine accessory drive cover, just in front of the fuel pump, had rubbed almost completely through the same hose. So in the interest of saving someone some money if they're near the end of their 4 year/700 hour warranty, figured I'd give you all a heads up so you can go check. I was installing a block heater anyway, so instead of screwing around taking the tractor in to the dealer, they just gave me the hose and I brought my old one in, installed it myself. Honestly, it takes longer for the coolant to drain than it does to change the hose. But one thing to note; I did end up trimming about 1" off the lower end of the hose. The new hose was slightly longer at the bottom and left the first bend too close for comfort to the motor mount bolt. The hose in question is #3 in the link. (crappy picture, but it's that one.) Also of note, the new hose doesn't really fit any better than the old one, so I positioned it the best I could and ziptied it in 2 spots to the main harness running down the radiator shroud. First pic I attached is the hose in reference to the engine. Second pic is the damage and bolt head.
Edit: Sorry, just realized it uploaded my pics rotated 90 degrees.