Coolant Concentration Testers
Due to a worldwide shortage of Ethylene Glycol, some coolant manufacturers
have started to mix other types of glycol into 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 other glycols present in the coolant.
All GM vehicles are produced with coolant you can accurately measure
with a hydrometer. However, when the type and quality of the coolant being
measured is unknown, such as a vehicle that has accumulated mileage, use a
refractometer.
Use coolant testers J 26568
or J 23688
to check the antifreeze
protection of the coolant. The markings of the refractometer must be correct.
Unless J 23688
or J 26568
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 manufacturer's directions
on using J 26568
or J 23688
.
Testing Procedure
Tools Required
• | J 23688 Coolant
Tester (Fahrenheit Scale) |
• | J 26568 Coolant
Tester (Centigrade Scale) |
Important:
• | Both J 23688
and J 26568
automatically compensate
for temperature. |
• | 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. |
- Release the tip of the pump from the housing of the J 23688
or the J 26568
.
- Do not remove the clear plastic pump from the J 23688
or the J 26568
.
Caution: As long as there is pressure in the cooling system, the temperature
can be considerably higher than the boiling temperature of the solution in
the radiator without causing the solution to boil. Removal of the pressure
cap while the engine is hot and pressure is high will cause the solution
to boil instantaneously -- possibly with explosive force -- spewing
the solution over the engine, fenders and the person removing the cap.
- Remove the surge tank/radiator cap.
- Insert the tip of the
pump into the surge tank/radiator. 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.
- Bend the tube around the J 23688
or the J 26568
. 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. Make
sure there is enough fluid on the measuring surface.