Freeze Protection, Checking
Special tools and workshop equipment required
- Refractometer T10007 A
The coolant reservoir is under pressure. Open only when the engine is cold.
Freeze protection must be guaranteed down to about -13°F [-25°C]), and in cold climate countries down to about -33° F (36 °C).
The amount of coolant additive must not exceed 55 % (freeze protection to -55° F (-48 °C))), otherwise the freeze protection will decrease and the cooling effect will worsen.
The coolant system should remain filled with freeze protection the entire year. A proper mixture ratio of coolant additive will prevent a build-up of calcium, freezing and corrosion damage and will raise the boiling point.
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.
Refractometer T10007 A must be used to determine the actual freeze protection.
Perform the Following:
-- Place a drop of coolant on the glass on the refractometer using a pipette.
A light-dark line is clearly visible on the "WATERLINE" scale.
-- Use the corresponding Refractometer T10007 A scale to determine the coolant freeze protection. Read the value on the bright/dark limit.
The refractometer scale -1- is designed for coolant additives G11, G12, G12+ and G12++.
The scale -2- is designed only for coolant additive G13.
If it is not possible to determine if the coolant additive was pure: use the scale for G13 to determine the frost protection.
The temperature on the Refractometer T10007 A corresponds to the >>crystalization point<<. At this temperature, the first flakes of ice begin to form.
-- Modify the composition of the coolant, if necessary, refer to "If the Freeze Protection is Insufficient :" below.
-- Check the freeze protection after the road test.
If the Freeze Protection is Insufficient:
-- Drain the pressure difference and fill with coolant additive.
| Freeze protection to | Coolant additive | Water |
|---|---|---|
| -13° F (-25 °C) | approximately 40 % | approximately 60 % |
| -33° F (36 °C) | approximately 50 % | approximately 50 % |
Approved frost protection additives .
G13 and G12++ may be mixed with the G11, G12 and G12+ coolant additives. However, this can worsen the corrosion protection.
Do not re-use used coolant.
Use only water/coolant additive as lubricant for the coolant hoses.