Determining Dilution Of Coolant

[CCI]

Reading here in the forum I see that somewhere around 50/50 ration of water to coolant concentrate is optimal and the freeze point is elevated by too much water and by too little water.

I'm looking at green coolant, it's clean, and the Prestone hygrometer says the freeze point is 7 degrees F. I'd like to see it be a lot lower than that.

I don't know the type of coolant or the maintenance history of the vehicle.

Is there any way to tell if this is a case of too much water or too little water?

 

[Jetronic]

All methods except freezing and looking at the temperature are correct to determine the concentration.

If you want to dible check, add a small amount of water to some of the green fluid and see what the hygrometer says.

 

[Lubener]

Reading here in the forum I see that somewhere around 50/50 ration of water to coolant concentrate is optimal and the freeze point is elevated by too much water and by too little water.

I'm looking at green coolant, it's clean, and the Prestone hygrometer says the freeze point is 7 degrees F. I'd like to see it be a lot lower than that.

I don't know the type of coolant or the maintenance history of the vehicle.

Is there any way to tell if this is a case of too much water or too little water?

Way too much water, too little anti freeze. To bring the concentration up to around 50/50, I would drain the radiator and refill with a 70% antifreeze with a 30% amount of water.

 

[Chris142]

It's too diluted with water. Drain some out and pour in concentrated coolant.

 

[eljefino]

Yeah the hygrometer measures specific gravity, it's not designed with the odd case that you actually have 100% antifreeze and also a freeze point of 7'F.

If you have any doubts, pull a measured amount and dilute it with more water, the rating will get worse, not better.

Since you don't know what's in there, I'd flush and start over. The anti-rust properties of the existing antifreeze are probably worn out. And you don't know if it's "old green" or all-makes green, the two of which don't appreciate mixing.

 

[Astro14]

Yeah the hygrometer measures specific gravity, it's not designed with the odd case that you actually have 100% antifreeze and also a freeze point of 7'F.

If you have any doubts, pull a measured amount and dilute it with more water, the rating will get worse, not better.

Since you don't know what's in there, I'd flush and start over. The anti-rust properties of the existing antifreeze are probably worn out.

The specific gravity of glycol and water differ, so, I think that hygrometer is accurate - if it were 100% glycol - it would peg out the hygrometer. Since it isn’t pegging it out, there isn’t enough glycol in the mix.

By the way, I’ve found that the refractomer is much more precise. The hygrometer is gathering dust since I got the refractometer.

 

[kschachn]

Reading here in the forum I see that somewhere around 50/50 ration of water to coolant concentrate is optimal and the freeze point is elevated by too much water and by too little water.

I'm looking at green coolant, it's clean, and the Prestone hygrometer says the freeze point is 7 degrees F. I'd like to see it be a lot lower than that.

I don't know the type of coolant or the maintenance history of the vehicle.

Is there any way to tell if this is a case of too much water or too little water?

Actually in terms of heat transfer what is optimal is the lowest glycol concentration that is acceptable for your climate. But also not below the manufacturer’s specified minimum (typically about 30%).

 

[KrisZ]

Fill your hygrometer with water to check that it will say 32F. If it does, it means it is working properly and your coolant mix is too weak, meaning it has too much water in it.

 

[JohnnyG]

I recently posted this to another thread, I'm sorry about that.
Anyway, these are available on Amazon, and are around $20.00. It will tell you the exact concentration of several types of fluids.
Is easy to use, accurate, and works well.

 

[CCI]

I recently posted this to another thread, I'm sorry about that.
Anyway, these are available on Amazon, and are around $20.00. It will tell you the exact concentration of several types of fluids.
Is easy to use, accurate, and works well.

Thank you!

 

[grisby]

FYI, a little off topic---I smoke cigars and have several humidors. I use hygrometers in my humidors to measure moisture(humidty) to keep my cigars fresh. Back on topic -- I think you would get better results in your test if you use a hydrometer

 

[NashNative]

I recently posted this to another thread, I'm sorry about that.
Anyway, these are available on Amazon, and are around $20.00. It will tell you the exact concentration of several types of fluids.
Is easy to use, accurate, and works well.
View attachment 199498

This is the correct tool...a portable refractometer is what should be used to determine the freeze point protection of a coolant/antifreeze.

 

[mr_boring]

FWIW - depending on your vehicle and how much it holds, I would either

A - drain and fill. Get it between 40% and 50%. It's not that hard to eyeball it to that range.
B - like mentioned above, just let a couple of quarts out and pour in a half gallon of concentrate. A half gallon won't get you anywhere near above 50% but it should get you down well below zero.

I think the tool you have is fine for a layman checking his/her mix once in a while. Sure, the real tool is like 20 bucks, but you probably won't use it more than 3-4 times.

I'd go for A since you don't know the history. It's almost 100% not factory - which means somebody either did coolant system work and didn't do it properly or some leaked out at some point and they topped up with water. Distilled if you are lucky - but why take a chance?

What kind of ride? It's pretty simple to use distilled water to flush system (will take a few gallons of distilled and a few days/cycles) then you drain ~half of the distilled out and pour in concentrate.

40-60% will run a system just fine. I'd be more concerned with tap water than the actual coolant being a little low. I messed up a Jeep Grand really bad on tap water. Ended up replacing a heater core AND all of the freeze plugs, and it was either the tap water or I just got a bad batch of coolant. Took less than a year for one of the freeze plugs to tap out, and a couple of the others were mighty close. All of that after a radiator replacement - not a mechanical or chemical problem, I hit a deer.

 

[vavavroom]

I use 40/60 coolant concentrate to water. If I need more freeze protection, which is rare, I go 50/50.

 

[zulf200]

Reading here in the forum I see that somewhere around 50/50 ration of water to coolant concentrate is optimal and the freeze point is elevated by too much water and by too little water.

I'm looking at green coolant, it's clean, and the Prestone hygrometer says the freeze point is 7 degrees F. I'd like to see it be a lot lower than that.

I don't know the type of coolant or the maintenance history of the vehicle.

Is there any way to tell if this is a case of too much water or too little water?

Buy a refractometer from amazon and check the coolant concentration then adjust as required.

I prefer to keep concentration at 50% as the coolant chemistry works best with it.

 

[zulf200]

FWIW - depending on your vehicle and how much it holds, I would either

A - drain and fill. Get it between 40% and 50%. It's not that hard to eyeball it to that range.
B - like mentioned above, just let a couple of quarts out and pour in a half gallon of concentrate. A half gallon won't get you anywhere near above 50% but it should get you down well below zero.

I think the tool you have is fine for a layman checking his/her mix once in a while. Sure, the real tool is like 20 bucks, but you probably won't use it more than 3-4 times.

I'd go for A since you don't know the history. It's almost 100% not factory - which means somebody either did coolant system work and didn't do it properly or some leaked out at some point and they topped up with water. Distilled if you are lucky - but why take a chance?

What kind of ride? It's pretty simple to use distilled water to flush system (will take a few gallons of distilled and a few days/cycles) then you drain ~half of the distilled out and pour in concentrate.

40-60% will run a system just fine. I'd be more concerned with tap water than the actual coolant being a little low. I messed up a Jeep Grand really bad on tap water. Ended up replacing a heater core AND all of the freeze plugs, and it was either the tap water or I just got a bad batch of coolant. Took less than a year for one of the freeze plugs to tap out, and a couple of the others were mighty close. All of that after a radiator replacement - not a mechanical or chemical problem, I hit a deer.

I think you suffered a grounding issue on your jeep if your core plugs were eaten away. Some coolants are not tolerant to electrolysis at all.