Coolant Tester - Calibration
90nissan06Classification: Section:
EM90-009 Engine Mechanical
Reference:
Technical Bulletin NTB90-093
Models:
All
Date:
October 18, 1990
COOLANT TESTERS
BACKGROUND INFORMATION:
Evaluations have shown that some after-market coolant testers displayed inaccurate readings which were, in some cases, off by as much as 10~F.
SERVICE INFORMATION:
When coolant concentrations are in question, the following advice is recommended to dealers:
1. Select a name-brand tester, preferably from a specialty tool supplier.
2. Prior to usage, calibrate the coolant tester:
^ Prepare a "known" mixture of exactly 50% fresh anti-freeze and exactly 50% fresh water. Keep this mixture in a clean, sealed container to use for calibration purposes.
^ To calibrate a coolant tester, draw from the above "known" mixture when it is at room temperature (65-75~F). Use a "Magic Marker" to place a mark on the coolant tester for the "known" 50/50 mixture.
^ Also, be sure that the coolant you wish to test is between 65-75~F. This means that you may have to wait for the temperature of the coolant to fall within this range.
NOTE: During extremely hot weather, it may be impractical to wait for the coolant to fall within the 65-75~F range. However, the coolant tester can be re-calibrated for the new, "hot weather" temperature using the "known" 50/50 mixture - provided both this 50/50 mixture and the coolant are at ambient temperature.
3. Measure the vehicle's coolant concentration using the calibrated mark on the coolant tester as an indication of a proper 50/50 solution.
NOTE: Technicians should be equally concerned if the coolant concentration is too high as well as too low. High coolant concentrations reduce the ability of the coolant to transfer heat, which, in some cases, may lead to over-heating. In extreme cases, the coolant can sludge and restrict flow in the radiator.
4. After use, clean the tester by flushing it with fresh water.
NOTE: Testing has shown that, if not properly cleaned, a non-soluble residue remains on the bouyant devices of the tooters after drying. This residue can effect the density of the bouyant devices and, consequently, effect the tester's accuracy.
If there are any further questions regarding coolant concentrations, please contact your Technical service Manager (TSM). The TSM's have access to laboratory-grade hydrometers.