Coolant, Filling

Coolant, Filling

The coolant system must be drained if larger components (for example, engine, radiator, etc.) are going to be removed and installed. Refer to => [ Coolant System, Draining ] Coolant System, Draining. Otherwise an incorrect filling will result due to air bubbles in the system. The cooling and heating systems will have temperature problems.

Special tools, testers and auxiliary items required

• Cooling System Charge Unit (VAS 6096)

• Adapter (V.A.G 1274/8)

• Refractometer (T10007 A)

Do not mix distilled water with coolant additives. Using distilled water provides optimum corrosion protection.

• The water portion of the coolant influences the effectiveness of the coolant. Volkswagen has decided to define the water quality used in the cooling system based on the different mixtures and country and regional requirements. Use distilled water.

• Use only coolant additives listed in the Parts Catalog. Other coolant additives may above all reduce the corrosion protection effect significantly. The damage resulting from this may lead to loss of coolant and consequently to severe engine damage.

• Coolant with the correct mixture ratio prevents freezing and corrosion damage and calcium deposits. The boiling point will be raised. The cooling system must be filled with coolant additive year-round.

• Because of its high boiling point, the coolant improves engine reliability under heavy loads, particularly in countries with tropical climates.

• Freeze protection must be guaranteed down to approximately -25 °C (-13 °F) (in arctic climatic countries down to approximately -35 °C (-31 °F)).

• The coolant concentration must not be reduced by adding water even in warmer seasons and in warmer countries. The coolant additive portion must be at least 40%.

• If a lower freeze protection is necessary due to the climatic conditions, increase the amount of coolant additive. The maximum amount is 60%. If the amount is increased beyond that, the freeze protection will be reduced and the cooling effect will be reduced.

• Do not reuse the old coolant again if replacing the radiator, heater core, cylinder head or cylinder head gasket.

• The refractometer (T10007A) is recommended for determining freeze protection density.

- Fill the coolant reservoir on the cooling system charge unit (VAS 6096) with at least 15 liters of premixed coolant of the proper mixture ratio:

• Coolant additive (40%) and distilled water (60%) for freeze protection down to -25 °C (-13 °F).

• Coolant additive (50%) and distilled water (50%) for freeze protection down to -35 °C (-31 °F).

• Coolant additive (60%) and distilled water (40%) for freeze protection down to -40 °C (-40 °F).

• For the correct coolant additive, refer to the Parts Catalog.

- Install the adapter (V.A.G 1274/8) to the coolant expansion tank.






- Install the cooling system charge unit (VAS 6096) to the adapter (V.A.G 1274/8).

- Close the levers - A and B - at a right angle to the flow direction.

- Place a air outlet hose - 1 - in a small container - 2 -.

• A small amount of coolant which should be collected is drawn off with the discharged air.

- Connect the hose - 3 - to the compressed air source.

• Pressure: 6 to 10 bar pressure.

- Open the lever - B - by turning the lever in the direction of flow.






• At least 0.7 bar vacuum must be produced.

- Briefly open the lever - A - by turning the lever in the direction of flow so that the hose on the cooling system charge unit (VAS 6096) coolant reservoir fills with coolant.

- Close the lever - A - again.

- Leave the lever - B - open another 2 minutes.

• A further vacuum is created in the cooling system by the suction jet pump.

- Close the lever - B -.






- Remove the compressed air source.

- Watch the pressure gauge. The vacuum may go down only to 0.4 bar. Check the coolant system for leaks if the vacuum continues to fall.

• The cooling system does not have any leaks if the vacuum falls but then stabilizes at a minimum of 0.4 bar.

• Perform the next filling slowly.

- Open the lever - A - slowly.






• Coolant is extracted from the cooling system charge unit (VAS 6096) coolant reservoir by pressure in the coolant system and the system is filled.

- Remove the cooling system charge unit (VAS 6096) from the adapter (V.A.G 1274/8) on the coolant reservoir.

- Check the coolant level inside the expansion tank. Fill or drain if necessary.






- Coolant concentration, checking. Refer to => [ Fill Quality, Checking ] Fill Quality, Checking.