Testing Coolant Concentration

Coolant Formulations
Due to a worldwide shortage of "Ethylene Glycol" in 1988, some coolant manufacturers have started to mix other types of glycol in their coolant formulations; propylene glycol is the most common new ingredient. A hydrometer will NOT always provide a correct measurement of freeze protection when anything other than ethylene glycol and water is being tested. The degree of inaccuracy will vary depending on the proportion of other glycols present in the coolant.

Refractometer
Some late model vehicles are produced with coolant that can be accurately measured with a hydrometer; however, when the type and quality of coolant being measured is unknown, such as a customer vehicle that has accumulated mileage, use of a refractometer is recommended.

J-23688, J26568, J-38633 Coolant Tester:

Coolant testers
Coolant testers J 26568 Centigrade Scale), J 23688 (Fahrenheit Scale) or 3863(Expanded Fahrenheit Scale) can be used to check the antifreeze protection of the coolant. Make sure the refractometer markings are correct. Unless J 26568, J 23688 or J 3863 has a provision for temperature correction, test the temperature at which J 26568, J 23688 or J 38633 is calibrated. If the coolant is warmer or cooler the reading may be incorrect. Follow the manufacturers directions on using J 26568, J 23688 or J 38633.

Cleaning The Coolant Tester:

CLEAN
^ Before each use, swing the plastic cover at the slanted end of J 26568, J 23688 or J 38633, exposing the measuring window and the bottom of the plastic cover.
^ Wipe dry with a tissue or a clean soft cloth.
^ Close the plastic cover.

MEASURE
1. Release the tip of the pump from J 26568, J 23688 or J 8633 housing.

Collecting The Coolant:

2. Insert the tip of the pump into the radiator filler neck.
^ Make sure the tip of the pump is below the level of the coolant.
3. Press and release the bulb to get a sample.
4. Insert the tip of the pump into the cover plate opening.
5. Press the bulb and allow a few drops to fall onto the measuring surface.
^ DO NOT open the plastic cover when taking readings because water evaporation can change the readings.

Reading The Coolant Tester:

6. Point J 26568, J 23688 or J 38633 toward any light and look into the eyepiece.
^ Coolant protection reading is at the point where the dividing line between light and dark crosses the scale (antifreeze protection is the scale on the right).
^ Temperature scale is reversed from a standard thermometer scale.
^ Below zero readings are on the upper half of the scale.
^ If the readings are not clear, the measuring surfaces was NOT cleaned and dried properly. Wipe dry and make a new test.