Coolant Additive, Checking And Filling
Coolant additive prevents freeze and corrosion damage, scaling, and raises the boiling point. For these reasons, the cooling system must be filled with radiator freeze and corrosion protection fluid all year round.
Use only approved radiator freeze and corrosion protection fluid for the different engine versions. Refer to appropriate FLUID CAPACITIES TABLE information in Maintenance. Using other coolant additives can impair the corrosion protectant. Loss of coolant and cause considerable damage to the engine.
Especially in countries with tropical climates or when vehicle is driven under heavy load, the coolant improves the engine reliability by its increased boiling point.
The coolant portion of the mixture must amount to at least 40% (freeze protection to -13°F [-25°C]) and should not exceed 60% (freeze protection to -40°F [-40°C]). Otherwise the freeze protection will be reduced and the cooling efficiency will be worsened.
The freeze protection must be ensured to approximately -13°F (-25 °C).
If climate conditions make greater freeze protection necessary, the amount of freeze protection can be increased up to 60%. Adding more coolant reduces the freeze protection and reduces the cooling efficiency.
Follow all waste disposal regulations!
Special tools and workshop equipment required
- Refractometer T10007
-- Check the concentration of the coolant additive using a refractometer T10007.
The scale -1- of the refractometer is designed for coolant additives G 12, G12 Plus, G12 Plus Plus and G11.
Scale -2- refers only to coolant additive G 13. (begins L80)
-- If the freeze protection is insufficient, fill according to the mixture ratio and then perform a road test.
-- Check the freeze protection after the road test.
Mixture Ratio
| Freeze protection to | Coolant additive | Water |
|---|---|---|
| -25°C (-13°F) | approximately. 40 % | approximately. 60 % |
| -35°C (-31°F) | approximately. 50 % | approximately. 50 % |
| -40°C (-40°F) | approximately. 60 % | approximately. 40 % |