Coolant Mystery

congrats on your new to you tractors, and welcome to the forum! all my tractors (cept one special one) are all newer than yours so I can't comment on what might be in those jugs like that (I don't know the answer), but there will be lots of others that can/will help you on this! and if'n you gits lots of snow....you can thank me later! lol

Normal if it had been setting. Drain plugs are at bottom where all foreign matter settles. MACM

I remember A-C sold "soluble oil" to add to the radiator fluid, as I recall it mixed with the coolant and became milky.  It was considered a preventative.  I don't think it would settle out, but maybe it did when the tractor sat.

Used dishwasher "tabs" a few years ago on a D17DIV that followed me home. Heart sank when "reddish oily residue" was visible in radiator filler neck the next day. Matted it out with a paper towel and did not get anymore (old additive?), cracked petcock on block and it was nasty so I figured I'd clean it up for new anti-freeze as she would be sitting for some time on the projects list.
Cut open a couple dishwasher tabs and dissolved them in a gallon of distilled water before adding to the radiator and filling with distilled water. Got her good and hot and left her at high idle, making sure she was circulating well. Sat a few days, got her hot and ran her again so she was circulating for sure before draining the nastiest crud you would want to see. Continued flushing with plenty of new distilled water fills before draining/filling with a decent name brand anti-freeze.
Temp gauge did show her running a bit cooler by the time I was done.

You mean like this stuff?

Welcome to the forum. I don't have alot to add except that I would be in the camp of checking compression and getting the ruff running one going even if she limps a little to plow right now. Take the other one completely apart and go through the motor or better yet wait for one of the wd 45 to get there and if neither one runs better rebuild one of them they have a little more power. But as long as the compression test looks ok I would do plugs wires points condenser cap rotor and if she still runs ruff get a carb cleaning. Electrical is all easy and probably the biggest problem you have with it not running well or would be my first guess. If you can get her out there at all you will have a much happier wife. And this life...lol   besides the way shameless is going you don't want to shove it all...
You said the motor oil looked black without antifreeze so I wouldn't worry about cross contamination if that was the case you would find a mix in both places or expect to anyway.

Edited by Dan73 - 16 Dec 2016 at 2:44pm

Welcome to the sight. When oil and water are in the same container the water always settles to the bottom. Like when water gets in theoil you loosen the drain plug a the water will come out before the oil.

The oil is probably black because it hasn't been changed for several years. Like others have said, get it running good if possible, check everything out and change the fluids. You'll get a good idea of what you have that way. By the way, welcome to the forum and before you know it you'll be helping others.

It seems like the consensus is that the oil was put there on purpose, and that the coolant should simply be replaced.  I would love to flush the system out before spending money on 3 new gallons of coolant, but alas the temps won't be above freezing here for many months.  Any tips for flushing the system out that doesn't require a hose and a heated garage with a drain?

My one bit of advice learned the hard way. I would replace the head bolts they are probably old and been out before. I rebuilt my d15 use the old bolts it seemed ok but I lost the head gasket pulled the head off and found nothing wrong replaced the gasket and in the process of torquing the bolts one broke before I even got to the final torque.   I got lucky and was able to get the bolt out but the thought of getting a broken head bolt out made me decide I would just get new head bolts in the future.

that should have read,dromus-b for the oil

no the radial engines ha 3 different rations of injection,you could use 100% distilled water,a 50/50 mixture of water and alchol or 60/40 mixture.all it did was increase the mixture mass going into the cylinder.but the main objective was to prevent detonation.you lost considerable power on take off with out it.the only time it was used was on takeoff power.....