Vehicles are produced with coolant that can be accurately measured with a hydrometer. However, when the type and quality of the coolant being measured is unknown, such as in a customer vehicle that has accumulated mileage, use of a refractometer is recommended.

Tools Required

Important: Do not remove the clear plastic pump from the J 26568 or theJ 23688 .

1. Before each use, swing the plastic cover at the slanted end of the J 26568 or the J 23688 , exposing the measuring window and the bottom of the plastic cover.
2. Wipe the cover dry with a tissue or clean, soft cloth.
3. Close the plastic cover.
4. Release the tip of the pump from the tester.



5. Insert the tip of the pump into the radiator filler neck. Make certain that the tip of the pump is below the level of the coolant.
6. Press the release bulb to get a sample.
7. Insert the tip of the pump into the cover plate opening.

Important: Do not open the plastic cover when taking readings because water evaporation can change readings.

8. Press the bulb and allow a few drops to fall onto the measuring surface.



9. Point the J 26568 or the J 23688 toward any light.
10. Look into the eyepiece at the following:

•	The 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).

•	The temperature scale is reversed from a standard thermometer scale. Below zero readings are on the upper half of the scale.

11. Wipe the surfaces dry and conduct the test again if the readings are not clear.