- Use a hydrometer to measure the specific gravity of the coolant (Fig. 5.6).
Fig. 5.6 Using a hydrometer to measure coolant density
- Measure the coolant temperature and, depending on the temperature, calculate the concentration of antifreeze in the coolant.
The relationship between the concentration of antifreeze in the coolant and the specific gravity
| Specific gravity at coolant temperature of 20°C, g/cm³ | Freezing point°C | Coolant concentration, % |
| 1,050 | -16 | 30 |
| 1,058 | -20 | 35 |
| 1,067 | -25 | 40 |
| 1,074 | -30 | 45 |
| 1,082 | -36 | 50 |
| 1,090 | -42 | 55 |
| 1,098 | -50 | 60 |
[The material was copied from the website mitsubishiman.ru]
Example
The freezing point of the coolant is -20°C with a weighted specific gravity of 1.058.
Warning: If the coolant concentration is below 30%, the anti-corrosion properties of the coolant are reduced. If the concentration is over 60%, the frost resistance of the coolant is impaired.