Tools Required
• | J 23688 Coolant
Tester (Fahrenheit Scale) |
• | J 26568 Coolant
Tester (Centigrade Scale) |
Some coolant manufacturers mix other types of glycol into their coolant
formulations. Propylene glycol is the most common new ingredient.
A hydrometer does not always provide a correct measurement of freeze
protection when anything other than ethylene glycol and water is being tested.
The degree of inaccuracy varies depending on the proportion of other glycols
present in the coolant.
All new GM 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, the use of a refractometer is recommended.
Coolant testers J 26568
(Centigrade Scale) or J 23688
(Fahrenheit Scale) can be used to check the antifreeze protection
of the coolant. Make sure the refractometer markings are correct. Unless J 26568
or J 23688
has a provision for temperature correction,
test the temperature at which J 26568
or J 23688
is
calibrated. If the coolant is warmer or cooler, the reading may be incorrect.
Follow the manufacturers' directions on using J 26568
or J 23688
.
Important:
• | Before each use, swing back the plastic cover at the slanted end
of the coolant tester, exposing the measuring window and the bottom of the
plastic cover. |
• | Wipe the measuring window dry with a tissue or a clean, soft cloth. |
• | Close the plastic cover. |
• | Do not remove the clear plastic pump from the J 23688
or the J 26568
. |
- Release the tip of the pump from the housing of the J 23688
or the J 26568
.
- Insert the tip of the
pump into the radiator filler neck. The tip of the pump must be below the
level of the coolant.
- Press the bulb. Release the pump bulb in order to obtain a sample
of the coolant.
- Insert the tip of the pump into the cover plate opening.
- Press the pump bulb. Allow a few drops to fall onto the measuring
surface. Do not open the plastic cover when taking readings because any water
evaporation will change the reading.
- Point the coolant concentration
tester toward any light source. Look into the eyepiece.
• | 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. |
- If the readings are not
clear, properly clean and dry the measuring surface. Conduct a new test.