KenPauling said:
Wait till you hear this! I asked a long time friend who sells used tractors and repairs them for the last 50 years about the correct antifreeze for my diesel. His reply was " any type" and you don't need to replace it. Just top it off if it gets low and you will be ok. The manufactures just want you to change antifreeze so they can sell more. He said he has never changed antifreeze in any of his tractors in 50 years! WOW!
I'd make it a point to NEVER buy a tractor from this guy

That's not the best advice I've heard today
Coolant can break down over time, loosing it's ability to withstand freezing temps. It can become acidic in time. Most new engines are NOT spotlessly clean inside the block casting. Dirt/rust/ect can dislodge over time (as the engine goes through heat/cool cycles) Coolant becomes contaminated. Those tiny bits of dirt and rust will erode metal on water pump impellors, insides of cylinder liners, and even clog radiators.
A combination of acidic coolant, dirt, and cavitation will literally eat holes in cylinder walls. I don't need to tell you what can go wrong when all the coolant suddenly has a way to dump into the oil pan.
I've bought several tractors over the years for pennies on the dollar of their full value because of wasted engines that were caused by lack of cooant system maintenance. The cylinder liners looked as if someone took a cutting torch and blasted tiny holes in them. One had LESS THAN 800 hours on the clock.
If a "tractor Jockey" buys and resells tractors strictly for a quick profit, generally they don't fix everything there is to fix to 100% levels. They fix what HAS to be fixed to get it turned around and off the lot. Would you go out to the nearest "Buy here Pay here" used car lot for advice on how to care for your new car that you plan on keeping for the next 10 years? Same applies to your tractor.
OR. Would you rather take a nickels worth of free advice from someone who's kept a tractor in excellent running order for 38 years?