D-6 coolant

sounds like he's been drinking the coolant himself . 1956 should be an 8u or 9u. ian.

Alcohol was used as a coolant before permanent type antifreeze, but alcohol will evaporate at engine operating temperatures, so the coolant level will need to be checked often.
It the alcohol is being burned, it is less likely to cause damage than antifreeze or water.

That Cat #5R3663 was made in 1945. The operations and maintenance book states that anti-freeze mixtures such as ethylene glycol, denatured methyl alcohol, methanol, and glycerine are all suitable for use. It further states that alcohol can be used successfully but, because it readily evaporates at the operating temperature of the diesel engine the solution should be tested frequently - even daily - and kept up to correct strength. This loss by evaporation is objectionable but the temperature regulator should not be removed.
I can't understand why anyone would not use ethylene glycol anti-freeze in today's world.
I have no comment about the diesel fuel, but I'm sure that someone here will chime in. John

I've heard lots of opinions on the reduced amount of sulfur being used in todays diesel fuel, I'm far from an expert, most of my stuff is older pre 1970 and for that equipment I add a litre of mineral based ATF (NOT SYNTHETIC!!) to every tank of fuel on my farm tractors, CATs etc. Just me but I believe that it adds additional lubrication for the old style injection pumps and the detergent helps keep everything clean, I've been doing this for 15 years or so. I have no proof that it helps BUT I have never done injectors or a pump in anything I own (knock on wood!!!!). My Freightliner gets Howes Diesel Treat every time we get a seasonal change of weather and my Dodge/Cummins gets some once a month or if it seems a little rougher than usual. (I have had guys tell me that the ATF wont mix with the diesel, it mixes just fine)
Just my opinion.😊

I have also been told to use mix some ATF with your diesel for extra lubrication and added power due to flammability of it. I would recommend that power service diesel additive, boost cetane rating(like octane rating in gasoline), cleans and helps lubricate. As far as the alcohol deal have never heard of using it as engine coolant, and if it is buring it there is issues with coolant being places is shouldnt i have this issue right know with my D6 9U.

Years ago when I was a kid alcohol was used most the time till Zerone and another one or two came out but thermostats weren,t too plentyful in engines then so they did get by with it.

Yep, you ran water most of the spring, summer, fall then waited as long as possible before putting "alcohol" antifreeze in! When glycol based antifreeze came along it was like relief and heaven all at the same time! One less thing to worry about.
As far as the D-6 having alcohol in the coolant, I agree that if it isn't boiling out or leaking out, then there is a bad gasket or crack somewhere?

SJ - Zerone and Zerex - one was permanent, the other was alcohol I do not remember which was which

Zerex was the permanent and the Zerone wasn,t.