Coolant concentration tester

[SilentType]

I changed the coolant yesterday in the 07 Jetta with Zerex G40.
I removed the return line from the reservoir and connected it to a long piece of tubing to drain the old stuff, all the while adding distilled water to the reservoir. Went through 4 gallons of distilled and it was running clear by the third gallon.

Started pouring G40 concentrate and only got about 3 quarts when the car decided to stop sending water out the return line, so I decided to button it all up and call it a day. The system is full and was burped the best I could do.

The problem is this is a 10 quart capacity cooling system so I know there is ~30 percent coolant now which isn't enough. The old school tester shows good to -43F. That can't be accurate with a 30 percent mixture can it? Are there any other testers needed for modern coolants?

This is what I'm using.

 

[Geekhead]

What is the coldest temp you expect in winter? I think what you have already would handle your worst day with ease. Or drain another quart or 2 and refill with the G40 if you want to travel to MInnesota and stay a few weeks in January to be safe.

 

[MasterSolenoid]

I would run the car for several days and check again.
Those testers are decent.
For simplicity, use what you have but verify with a tester that has floating balls.
Those are two inexpensive testers that have been around a long time.

I use a 'refractometer' (most accurate).
But I also had an inexpensive one 'stop' working.

 

[SilentType]

The past 3 winters we've gotten down to about +7F for a few days. A 50/50 coolant mix would set my mind at ease I suppose.

 

[Snagglefoot]

I’m trying to figure out what you did. Did you possibly watch a hack video on you tube? There is nothing wrong with the tester you showed, however, I don't think you drained your block. How about if you post a video from you tube showing the technique you might have used.

 

[doitmyself]

I've had coolant concentration issues with my workplace agriculture vehicle and equipment fleet over the decades. Either the coolant volume numbers were wrong in the manuals and/or I had issues with cheap testers.

I invested in a good refractometer and never looked back. You can test a refractometer using plain tap water and using a known 50/50 mix of coolant/water.

 

[zzyzzx]

I use the above shown tester (multiple times, and backcheck against known 50/50 mix and water) AND the floating ball type tester. My emphasis being on using more than one type of tester multiple times to make sure.

 

[SilentType]

I’m trying to figure out what you did. Did you possibly watch a hack video on you tube?

Lol guilty as charged. It's very possible all the old coolant didn't get removed. I watched a video that did it that way and some of the Volkswagen forums had said the method would work. Maybe it don't!

 

[Snagglefoot]

I'll let the Volkswagen folks chime in, but I believe part of the problem might be there might not be drain on the radiator. In that case you would have to remove the plastic belly pan, and drain the coolant by detaching the hose to the rad. Reattach the hose. Fill with distilled water and drive. Then let cool. Detach the hose and drain. You might even want to do the procedure one more time. After the last time, drain the rad and re-attach the rad hose. Fill the rad with 100% coolant. Take it for a drive. Let cool and then test it with your tester. You would be close to 50/50. If the Volkswagen folks have a better technique, please post it.

If the concentration is not high enough, drain the rad one more time and fill with 100% coolant. Discard the water/antifreeze mixture you drained on the last attempt. You will now have a higher concentration.

 

[JohnnyG]

I changed the coolant yesterday in the 07 Jetta with Zerex G40.
I removed the return line from the reservoir and connected it to a long piece of tubing to drain the old stuff, all the while adding distilled water to the reservoir. Went through 4 gallons of distilled and it was running clear by the third gallon.

Started pouring G40 concentrate and only got about 3 quarts when the car decided to stop sending water out the return line, so I decided to button it all up and call it a day. The system is full and was burped the best I could do.

The problem is this is a 10 quart capacity cooling system so I know there is ~30 percent coolant now which isn't enough. The old school tester shows good to -43F. That can't be accurate with a 30 percent mixture can it? Are there any other testers needed for modern coolants?

This is what I'm using.View attachment 308717

$25.00 from the jungle store:

 

[gman2304]

Coolant test strips?

 

[Snagglefoot]

$25.00 from the jungle store:View attachment 308756

This is a nice tool, but when working with coolant, you need to know if the concentration is 10%,20%,30%,40%,50% or 60%, not 50.07%. That accuracy is simply not required. I need 60% in the cold region I will be operating the vehicle. At $25 add the tool to your stash, but it won't change the outcome.

 

[Snagglefoot]

Here is a simple video of Prestone's tester there are various suppliers of them and they are sufficiently accurate for anti-freeze work on vehicles. I often drive to Edmonton where is can be -40 F or C. Your choice.

https://ca.video.search.yahoo.com/y...tube&type=fc_A69BE08F2A5_s69_g_e_d_n3003_c999

 

[johnmyster]

Prestone specific gravity tester is $3 at walmart.

You likely still had 50/50 mix in your block. So you mixed that in with whatever amount of concentrate you introduced into the portion of the circuit you drained and filled.

Drive the car long enough to get the system mixed and retest. From there, decide if you need to bleed to make additional room for either water or concentrate.

Best method is to break hoses in a few places. Flush extensively with garden hose water. Blow down with compressed air. Reconnect hoses. Add 1/2 system volume of concentrate. Gradually add distilled water until system is minimum fill. Drive car to mix. Test with hygrometer. Top off tank with concentrate or water depending on desired final concentration. Optionally you can do a citric acid cleaning cycle while everything is full of water.

 

[SilentType]

Coolant change for Volkswagen:

 

[JohnnyG]

This is a nice tool, but when working with coolant, you need to know if the concentration is 10%,20%,30%,40%,50% or 60%, not 50.07%. That accuracy is simply not required. I need 60% in the cold region I will be operating the vehicle. At $25 add the tool to your stash, but it won't change the outcome.

Maybe this will help you:

Last I heard, it wasn't wise to go much over 60% concentration on Dexcool at least. Not sure about other formulations.
This is the view through the tool that I posted. Oh yeah, it does batteries too, as well as Propylene Glycol.

 

[Snagglefoot]

Maybe this will help you:View attachment 308794
Last I heard, it wasn't wise to go much over 60% concentration on Dexcool at least. Not sure about other formulations.
This is the view through the tool that I posted. Oh yeah, it does batteries too, as well as Propylene Glycol.

Yes, going above 60% concentration of ethylene glycol based coolant is counter productive and will actually raise the freezing point. Mods, this chart has been published by many sources and is required to show the relationship between concentration and freezing temp.

 

[The_Jeff]

Refractometers are the bee's knees. A quick web search will show the same exact one on Temu, Amazon, Ebay, etc. Only once you look through your own will you appreciate the precision.

Floating ball doohickeys are hot garbage in comparison.

 

[AdrianH]

An example of 50% from a recent fleet inspection

 

[Joba27n]

Not like it would be a big deal (in my opinion) for your area but Toyota had an old bulletin from the Toyota red (LLC) coolant days where they stated for best heater operation, 55% antifreeze to water was the max they recommended. More antifreeze than that reduced the heat transfer abilities of the coolant. Or to be exact it said heat transfer was not "stable" above a 55% concentration.

Not sure how that compares with other coolants but if it helps I use the SLLC pre-mix in one of my vehicles which is 55/45 in Canada and has a stated freeze point of -37*C. I encounter down to -43*C and the coolant didn't slush after a couple days of sitting not plugged in.