Antifreeze %

[DaveUK]

In the piece about cleaning the radiator, it says not to use more than 25% antifreeze as it can affect the movement of the cooling water on tractors without a water pump.

But what happens if I need greater than 25% because of the winter temperature outside?

 

[Bird]

In the piece about cleaning the radiator, it says not to use more than 25% antifreeze as it can affect the movement of the cooling water on tractors without a water pump.

But what happens if I need greater than 25% because of the winter temperature outside?

Dave, I guess you're talking about a post in the Yanmar forum, and I'm not sure what the reason was for the 25% figure; whether Yanmar recommends that or whether the poster was considering the temperature where the original poster lives, or just what. And of course, I don't know what kind of tractor you have. But I had a 1995 Kubota B7100 with no water pump and the manual recommended a maximum of 50% which is what I ran with no problems.

I did a little more checking and found that 25% number apparently came from Hoye Tractor and they certainly know a great deal more than I about Yanmars (and probably nearly all other tractors, too).

 

[Sockwell]

If I'm not mistaken, 100% antifreeze has a freezing point not much lower than water, somewhere around 25F. If not mistaken, the old Prestone jugs use to say the optimal mix was 70% water, 30% antifreeze.

 

[Bird]

If I'm not mistaken, 100% antifreeze has a freezing point not much lower than water, somewhere around 25F. If not mistaken, the old Prestone jugs use to say the optimal mix was 70% water, 30% antifreeze.

I believe you may have that backwards. I think 70% antifreeze and 30% water was for maximum protection in the lowest temperatures and that's still what they recommend today. However, in all but the most extreme cold, a 50/50 mix is adequate and if you buy the pre-mixed (which didn't exist in my younger days when I was selling antifreeze, servicing cars, etc.), as far as I know, it only comes in a 50/50 mix. Of course, we used to have charts showing the different freezing points for different ratios and they may still have that on the jugs. In warmer climates, a 30% antifreeze and 70% water may be all you ever need to prevent freezing.

Maybe some more of you are old enough to remember when we used to drain the antifreeze in the Spring, flush the radiator, then fill it with fresh water, and perhaps a can of water pump lubricant/rust inhibitor. Then in the Fall, flush it again and fill with fresh water and antifreeze.

 

[Willl]

 

[Bird]

Very good! I knew in my part of the country that 50% was stronger than needed as far as freeze protection. But of course antifreeze also contains some water pump lubricant, so 50% never hurt anything as far as I knew, but maybe some machines with the thermosyphon instead of a water pump might be better off with the lower ratio.

 

[DaveUK]

Yes, sorry, it was in the Yanmar forum. I read it in a piece by Hoye about the 25%, but I need to protect down to -30C, which looks around 40%. But will the coolant flow properly with this concentration in a Yanmar 1700?

 

[Egon]

There are testers that tell you to what temperature your antifreeze will protect.

 

[Bird]

will the coolant flow properly with this concentration in a Yanmar 1700?

I can't say for sure, but I'll bet it would. You have to remember that Hoye Tractor is in Texas (hot climate) so you'd be concerned about the flow keeping the engine cool. In a cold environment, you might need less flow. And that's just my guess. Why don't you call Hoye Tractor or send them an e-mail and see what they say.

 

[KennyV]

I've always ran 50/50 in my IH cub F (no water pump) year round for many decades, never had any coolant flow problems.
If there would have been any type of flow problem it should have showed up while working it VERY hard in hot summer weather.