Procedures
Cooling System, Draining and Filling
Special tools, testers and auxiliary items required
• Adapter (V.A.G 1274/8)
• Adapter V.A.G 1274 tester (V.A.G 1274/10)
• Hose clamp pliers (V.A.G 1921)
• Cooling system charge unit (VAS 6096)
• Drip tray for workshop crane (VAS 6208)
• Refractometer (T10007)
Draining
• Drained coolant must be stored in a clean container for disposal or reuse.
CAUTION!
Cover cap of expansion tank with rag and open carefully, as hot steam i.e. hot coolant may escape when opening.
- Open cap of coolant expansion tank.
- For vehicles with auxiliary heater, remove bolts - arrows - for exhaust pipe of parking heater/auxiliary heater on noise insulation.
- Loosen quick-release fasteners - 1 through 3 - and remove front and rear noise insulation.
- Place drip tray for workshop crane (VAS 6208) under engine.
- Disconnect coolant hose - arrow - from oil cooler and drain coolant.
- Disconnect lower right coolant hose from radiator - arrow - and drain residual coolant.
Filling
• Ignition switched off.
• The cooling system is filled all year round with a mixture of frost and corrosion protection additives and water.
• Only use one of the frost and corrosion additives approved for this vehicle. 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.
• 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.
• Freeze protection must be assured to about -25 °C (in arctic climatic countries to about -35 °C).
• 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 increased freeze protection is needed because of the climate, the amount of G12+ can be increased, but only up to 60% (frost protection to about -40 °C), otherwise the freeze protection and cooling effectiveness will be reduced.
• Only use clean drinking water for mixing coolant.
• Do not use drained coolant in the following situations:
• If the radiator, oil cooler, heat exchanger, cylinder head, cylinder head seal or cylinder block were replaced.
• If coolant is contaminated.
• Use refractometer (T10007) to determine the level of freeze protection in the coolant system.
• Secure all hose connections with hose clamps appropriate for the model.
- Connect coolant hose to oil cooler - arrow -.
- Connect coolant hose - arrow - to connector on the radiator.
- Remove old O-ring - 2 - in coolant hose - 3 -.
- Moisten new O-ring with coolant additive and install it in the coolant hose.
- Press coolant hose onto radiator - 1 - or coolant pipe until it engages.
- Press coolant hose on again and pull to make sure connection is engaged correctly.
- Fill replacement reservoir (VAS 6096/1) with at least 12 liters of pre-mixed coolant with correct mixture ratio:
• Coolant freeze and corrosion protection additive (40%) and water (60%) for freeze protection up to -25° C.
• Coolant freeze and corrosion protection additive (50%) and water (50%) for freeze protection up to -35° C.
• Coolant freeze and corrosion protection additive (60%) and water (40%) for freeze protection up to -40° C.
- Place air outlet hose - 1 - into a small container - 2 -. (A small amount of coolant is drawn off which should be reserved with the discharged air.)
- Close both valves - A - and - B - by turning lever perpendicular to direction of flow.
- Connect hose - 3 - to pressurized air.
• Pressure: 6 to 10 bar pressure.
- Open valve - B -, turn lever in direction of flow to do this.
A vacuum is created in the cooling system by the suction jet pump.
• Needle on the instrument display must travel into the green region.
- Also briefly open valve - A -, turn lever in direction of flow to do this, so that hose of the replacement reservoir (VAS 6096/1) is filled with coolant.
- Close valve - A - again.
- Let valve - B - remain open another 2 minutes.
• A further vacuum is created in the cooling system by the suction jet pump.
• Needle on instrument display must still remain in the green region.
- Close valve - B -.
• Needle in display must remain in green region, then vacuum in cooling system is sufficient for subsequent filling.
If needle stands below the green region, repeat procedure.
If vacuum decreases, cooling system is leaking.
- Disconnect pressurized air hose.
- Open valve - A -.
The vacuum in the cooling system has the effect of extracting coolant from coolant reservoir (VAS 6096/1); cooling system is filled.
- Remove cooling system charge unit (VAS 6096 ) from coolant expansion tank.
- Connect adapter for VAG1274 tester (V.A.G 1274/10 ) to adapter (V.A.G 1274/8).
- Loosen coolant hose to heater core and pull back hose sufficiently so that the bleeder hole - arrow - in coolant hose is no longer sealed by the connection.
- Fill up coolant until it escapes from coolant hose bleeder hole.
- Push coolant hose onto connection and secure it with spring-type clamp.
- If present, switch on auxiliary heater for about 30 seconds.
- Twist cap for expansion tank closed.
- Start engine.
- Set temperature at "HI".
- Switch A/C compressor off by pressing ECON button.
- Let engine run at 2000 RPM for 3 minutes.
- Let engine run at idle long enough until both large coolant hoses on main cooler are warm.
- Let engine run at 2000 RPM for 1 minute.
- Turn off engine and allow it to cool off.
- Check coolant level.
• With cold engine, coolant level must be at MAX marking.
• Coolant level may be above MAX marking with engine at operating temperature.