Coolant Concentration Testing
WARNING: This page is about a different car, the 2025 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
Do not mix types of coolant - corrosion protection will be severely reduced.
CAUTION:
Do not use coolant additives that are claimed to improve engine cooling.
Check coolant concentration when any additional coolant is added to the system, or after a coolant drain, flush and refill. Use of a hydrometer or the Refractometer [special tool # 8286] can be used to test coolant concentration.
- A hydrometer tests 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 the higher the freeze protection (up to a maximum of 60% by volume glycol).
- The Refractometer [special tool # 8286] tests 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 manufacturers use other types of glycols in 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 are not recommended.
- Visually inspect the coolant for contamination. Must be free of oil, dirt and/or other materials that can adversely affect the cooling system.
- If the coolant is found to be contaminated after a visual inspection, discard the coolant.
- If the coolant is found to be clear of contamination after a visual inspection the test the coolant concentration.
- Using a Refractometer [special tool # 8286] or equivalent, following the manufacturer's instructions, test the coolant freeze point:
- If the coolant freeze point is between -31°C and -45°C (-25°F and -50°F), save the coolant for reuse.
- If the coolant freeze point is not between -31°C and -45°C (-25°F and -50°F), discard the coolant.