Grand Voyager V6-3.8L VIN L (1999)
Coolant: Testing and Inspection
Coolant concentration should be checked when any additional coolant was added to system or after a coolant drain, Rush and refill. The coolant
mixture offers optimum engine cooling and protection against corrosion when mixed to a freeze point of -37°C (-34°F) to -59°C (-50°F). The use of a
hydrometer or a refractometer can be used to test coolant concentration.
Hydrometers test the amount of glycol in a mixture by measuring the specific gravity of the mixture. The higher the concentration of ethylene glycol,
the larger the number of balls that will float, and higher the freeze protection (up to a maximum of 70% by volume glycol).
Refractometers test the amount of glycol in a coolant mixture by measuring the amount a beam of light bends as it passes through the fluid.
Some coolant manufactures use other types of glycols into their coolant formulations. Propylene glycol is the most common new coolant. However,
propylene glycol based coolants do not provide the same freezing protection and corrosion protection and is only recommended for limited usage.
Refer to appropriate Technical Service Bulletin(s) regarding use of propylene glycol based coolants.
CAUTION: Do not mix types of coolant. Corrosion protection will be severely reduced.
Because ethylene glycol and propylene glycol do not have the same specific gravities, the use of a hydrometer will be inaccurate. Therefore, Special
Tool 8286 refractometer, must be used when testing coolant.
