Cooling System, Draining And Filling: Filling
The cooling system is filled all year round with a mixture of frost and corrosion protection additives and water.
Frost and corrosion protection additives prevent freezing and corrosion damage and scaling. They also raise the boiling point. For this reason the system must be filled all year round with frost and corrosion protection additives.
Because of its high boiling point, the coolant improves engine reliability under heavy loads, particularly in countries with tropical climates.
Protection against frost must be assured to about -25 °C / -77 °F (in arctic climatic countries to about -35 °C / -95 °F).
The coolant concentration must not be reduced by adding water even in warmer seasons and in warmer countries. Coolant additive portion must be at least 40%.
If increased freeze protection is needed because of the climate, the amount of G12+ can be increased, but only up to 60% to provide freeze protection to about -40 °C / -104 °F. Otherwise the freeze protection and cooling effectiveness will be reduced.
Only use clean drinking water for mixing coolant.
If radiator, heat exchanger, cylinder head or head seal or cylinder block were replaced, do not reuse used coolant.
Dirty coolant must not be re-used.
Use the refractometer T10007 to determine the level of freeze protection in the coolant system.
-- Connect coolant hose on bottom of radiator -arrow-.
Ignore -1-.
-- Connect coolant hose to after-run coolant pump -V51- -arrow-.
Coolant hoses are shown on a vehicle with direct shift automatic transmission (DSG).
-- Fill coolant reservoir on VAS 6096 with at least 10 liters of premixed coolant with the proper mixture ratio:
- G12+ (40%) and water (60%) for freeze protection down to -25 °C / -77 °F
- G12+ (50%) and water (50%) for freeze protection down to -35 °C / -95 °F
- G12+ (60%) and water (40%) for freeze protection down to -40 °C / -104 °F
-- Attach V.A.G 1274/8 to coolant reservoir.
-- Install VAS 6096 on adapter V.A.G 1274/8.
-- Place air outlet -1- in a small container -2-.
A small amount of coolant which should be collected is drawn off with the discharged air.
-- Close valves -A- and -B- by turning lever at a right angle to direction of flow.
-- Connect hose -3- to compressed air.
- Pressure: 6 to 10 bar pressure.
-- Open valve -B- by turning level in direction of flow.
- The suction jet pump generates pressure in the coolant system; indicator on display instrument must move into green area.
-- Briefly open valve -A- by turning lever in direction of flow so that hose on VAS 6096 coolant reservoir fills with coolant.
-- Close valve -A- again.
-- Leave valve -B- open another 2 minutes.
- More pressure is generated in the coolant system by the suction jet pump; indicator on display instrument must stay in green area.
-- Close valve -B-.
- Needle in the display instrument must remain in the green region, then the sufficient vacuum in the cooling system is obtained for the upcoming filling.
If needle stands below the green area, repeat procedure.
If pressure falls, check coolant system for leaks.
-- Remove pressurized air hose.
-- Open valve -A-.
- Coolant is extracted from the VAS 6096 coolant reservoir by pressure in the coolant system and the system is filled.
-- Check coolant level.
-- Fill coolant up to "max" marking.
-- Start engine and run at approximately 1500 RPM for a maximum of 2 minutes.
-- With engine running, fill coolant up to overflow hole on coolant expansion tank.
-- Close cap on coolant expansion tank.
-- Start engine and run it until coolant fan starts running.
Risk of scalding due to hot steam and hot coolant.
- When the engine is warm the cooling system is under pressure.
- Reduce pressure by covering coolant reservoir cap with a cloth and carefully open.
-- Check coolant level.
- With engine warm, coolant level must be at "max" marking, with cold engine, between "min" and "max" marking.
-- If necessary, top off with coolant again.
-- Shut off engine.