Notes on coolant - AH20.00-N-2080-01A
All engines
Coolant composition
Passenger car and commercial vehicle engines (normally): 50% water by volume and 50% anticorrosion/antifreeze agent by volume.
A different coolant composition for CV engines, refer to MB Specifications for Operating Fluids
Tasks of the anticorrosion/antifreeze agent
- Corrosion and cavitation protection for all components in cooling system
- Antifreeze protection (frost protection)
- Increasing the boiling point so that coolant does not evaporate so rapidly. Avoiding ejection of coolant at high coolant temperatures.
Antifreeze protection
50% anticorrosion/antifreeze agent by volume provides antifreeze protection down to approx. -37°c A higher concentration is only necessary if the ambient temperatures are even lower. 55% anticorrosion/antifreeze agent by volume provides antifreeze protection down to approx. -45°C
A concentration of more than 55% anticorrosion/antifreeze agent by volume should not be used as the maximum antifreeze protection is already reached at this concentration. An even higher concentration reduces the antifreeze protection again and impairs heat dissipation. Reduced heat dissipation can result in damage to components of the cooling system and to the engine.
Water
Use water which is clean and not too hard. Drinking water often satisfies requirements, but not always The amount of dissolved substances in the water may be of significance for the occurrence of corrosion. If in doubt, analyze the water. For fresh water specifications refer to MB Specifications for Operating Fluids.
Operational monitoring of coolant
Inspect the antifreeze protection of the coolant before the start of the cold season.
In countries with high ambient temperatures, inspect concentration of anticorrosion/antifreeze agent once a year. The corrosion protection in the coolant gets depleted during operation. Old coolant for which the corrosion protection is virtually completely exhausted has a very corrosive effect.
Period of use
The maximum permissible period of use of the coolant is given in the maintenance booklet, the applicable "Service/Maintenance Sheet" or the MB-Specifications for Operating Fluids.
For the period of use for a varying coolant composition for CV engines, refer to MB Specifications for Operating Fluids.
Before pouring in fresh coolant, flush the used coolant out of the cooling system.
In the case of severe fouling by dirt or oil, clean the cooling system otherwise components of the cooling system can be damaged.
If drained off coolant is used again it is absolutely essential that the coolant is filtered in the cooling system before being poured in again.
No dirt particles should be allowed to enter the cooling system otherwise damage can occur to components of the cooling system.
Disposing of coolants
Observe the legal provisions and local waste water regulations.