Tractor neglect...

Ok, maybe not real bad neglect, but need some advice.
Works been real busy and I really haven't started either tractor in at least 3 months or even paid much attention to them. Ran the loader tractor just enough to move it one day last month.
Anyways, with this cold snap, it hit me this morning over breakfast that I cannot recall if I have proper antifreeze levels in the 641 and the 4140 (both gas engines).
So, out to the unheated shop with a flashlight to check, fearing the worst. No obvious leaks or damage, but when I opened the radiator caps, both are dry. Dry as in I don't see any water/antifreeze, just an empty radiator. Then I remembered I really don't recall the last time I checked those fluids. Good chance they've been low for sometime now.
So... at this point should I just add antifreeze? I'm a little hesitant to try to start either one as i have no idea if their frozen or not. Anyway to easily tell?
Thought about opening the drain at the bottom of the radiator see what I get, and may do that this weekend when I am able to get them out and it is daylight.
Almost feels like I forgot to feed the dogs...

Thanks
Tony

I would check the oil first and make sure it is not over full and hope it is not because that could be bad. Me I would then fill wit ha 50/50 mix or better of antifreeze. When I say better the max protection is a 70% antifreeze to 30% water

I think you're on the right track, open the drain or the petcock on the
engine if it has one (or both) and see what you get.
If you get antifreeze, good.
Add 50/50 mix until you can see it, run it and test the antifreeze.
If the tester says its good, finish filling with 50/50.
If its a little low on the protection, add 70/30 as Old mentioned.
If its a lot low, you may need to change it.
Of course, if its been a long time, changing it wouldn't be a bad idea either.
Just a cold time of year to try to do the drain and flush routine.

"If the tester says its good, finish filling with 50/50.
If its a little low on the protection, add 70/30 as Old mentioned."

I would suggest adding straight anti-freeze, not 70/30 to top off if the protection is low, as that will bring you up towards the 50/50 or 70/30 that is ideal that much quicker!
JMHO, HTH, Dave

check oil too.. make sure it's not a few inches high..

I have done that, if you can wait til the temp is above freezing that is what I would do, damage if any is already done. A small amount of antifreeze can protect the block from cracking but still freeze in the radiator and couse overheating if you try to fun the engine.

Forgot to mention, the oil levels were both a bit low (more neglect...). So that could be some good news, or it just means nothing has thawed and ran into the oil...
I normally run my cars a little heavy on the antifreeze mix, and I would think i did the same the last time I flushed the tractors, but that would have been early fall over a year ago and I just can't remember if I did that or filled with water until I could get some antifreeze and then forgot...

I'd say if your not sure what is in either tractor then that would be a sign to me that it's time to drain, flush and put new antifreeze in it. I replaced the water pump in my 4600 this summer and I actually "thought" that one was well maintained. I regularly check the antifreeze level and temperature rating, but whan I drained it to replace the pump it was the nastiest rusty mess I have ever seen drain from a radiator. I flushed the rad and engine several times and promised myself I would maintain it more often. Just my thoughts.

put your ear near the radiator neck and
squeeze the bottom hose.
Can you squeeze it? and can you hear liquid moving?
if ok, top it off with straight antifreeze.
If it's not frozen, you must start it after adding fresh, to get it to mix.
otherwise, the block will still have weak in it.
still not strong enough?, drain a gallon or two and top it off with straight again.
up here in the North, I never add straight water,
and I won't buy pre-mix.
If I mix it myself, I know what I have