Prestone Vu Chek

[grpass]

I picked up a Prestone Vu-Chek battery and Antifreeze tester. I'm looking for the instructions. And if it has a battery, how to change it. Thanks. Probably from the 60,s.

 

[signcrafter]

It's a refractometer. Probably going to have to get the clear cover cleaned to be usable. You put a drop of fluid on the little black area and then close the cover. Hold to light source and look in the end. Should have a scale of some sort you can see and should be able to see the concentration of the fluid on that scale.

 

[RTM]

And no battery.

 

[grpass]

Thanks.

 

[66HertzClone]

You will need to verify this but, if that was intended for the old ethylene glycol coolant it won't give you an accurate reading with the new long life coolants.

 

[dscheidt]

You will need to verify this but, if that was intended for the old ethylene glycol coolant it won't give you an accurate reading with the new long life coolants.

If the refractometer gives the refractive index directly (and not just the precalculated concentration of old-fashioned Prestone), you can use that. Coolant manufacturers publish the RI of their products, and so you can convert. If it just gives a freeze point number, you'd have to work the RI out of that, and then convert from there. But the differences are small, most coolants are still ~95% ethylene glycol (before you dilute them), and the difference is the additive package.

 

[grpass]

If the refractometer gives the refractive index directly (and not just the precalculated concentration of old-fashioned Prestone), you can use that. Coolant manufacturers publish the RI of their products, and so you can convert. If it just gives a freeze point number, you'd have to work the RI out of that, and then convert from there. But the differences are small, most coolants are still ~95% ethylene glycol (before you dilute them), and the difference is the additive package.

That's why I like this forum, so more information.

 

[ChevyEFI]

It's a refractometer. Probably going to have to get the clear cover cleaned to be usable. You put a drop of fluid on the little black area and then close the cover. Hold to light source and look in the end. Should have a scale of some sort you can see and should be able to see the concentration of the fluid on that scale.

I don't know of it matters on this specific one. But dipping the cover into the fluid and rotating it so it is over the black window is how we use our work refr. for a water / oil mix coolant.

The line visible "behind" the graph is tough to see, even with good light and focus adjustment of the eyeview end.

 

[signcrafter]

Have you tried to look in it and see if you can even read the scale yet? Unless you're into the vintage look I think I would just spend the 22 bucks for a new one, https://www.amazon.com/Antifreeze-C...indshield/dp/B07DLDZFJX/?tag=atomicindus08-20. It won't be faded and should be able to read it better and won't have to worry if it works with new coolants or not. I have a blue point one I bought probably 7-8 years ago but it looks similar to the one I linked.

 

[Schurkey]

LABELED "Prestone". Actually made by Reichert/Leica. My high-school "Engine Mechanics" teacher had one, and I thought it was so cool that years later I got one of my own. Made in USA, calibrated in Freedom degrees instead of Chinese degrees--although C calibration was available.



Underside holds a bulb/tube for sucking up a coolant sample, and a black plastic dipstick for battery acid.


Mine shows scales for Ethylene glycol, Propylene glycol, and battery acid (sulfuric acid). Bought it off of a tool truck--probably Mac--decades ago (later 1980s.) I suppose you could test DEF and washer fluid--maybe--but you'd have to look at known-good samples and remember where the indication was because there's no scale for them.

Newer-version user manual, but seems to be functionally identical to ours.

https://res.cloudinary.com/iwh/image/upload/q_auto,g_center/assets/1/26/Reichert_Rhino_Duo-Chek_User_Guide.PDF

Calibration is PROBABLY not going to be needed, if the unit is cleaned-up properly. If you absolutely HAVE to play with the calibration, the screws are sealed under some RTV Silicone sealer behind the underside data panel which slides out. I have never touched the calibration of mine.

 

[Schurkey]

going to have to get the clear cover cleaned to be usable.

Absolutely.

You put a drop of fluid on the little black area and then close the cover.

Having been cleaned from the previous use, I leave the clear-plastic cover CLOSED, and put a drop of fluid in from the eyepiece-side of the plastic cover. The fluid flows over the textured bottom surface of the clear plastic, wetting the entire black area. If there isn't enough fluid, (or enough ambient light) you don't get a good indication.

After taking the reading, then I flip the cover up for cleaning the cover and the black area...and any fluid that drizzled anywhere else.

Hold to light source and look in the end. Should have a scale of some sort you can see and should be able to see the concentration of the fluid on that scale.

Brighter the light, the better the indication. It is a mild pain in the tuckus to hold it up towards the overhead lights, or the sky.