Cooling System: Service and Repair
Coolant, Draining and Filling
Special tools, testers and auxiliary items required
• Adapter (V.A.G 1274/8) Adapter for V.A.G 1274 Tester (V.A.G 1274/10)
• Hose Clip Pliers (V.A.G 1921)
• Cooling System Charge Unit (VAS 6096)
• Drip Tray for VAS 6100 (VAS 6208)
• Refractometer (T10007)
Draining
• Collect escaping coolant in a clean container for disposal or reuse.
Risk of scalding due to hot steam and hot coolant.
• The coolant system is under pressure when the engine is warm.
• Reduce pressure by covering coolant reservoir cap with a cloth and carefully opening.
- Open the coolant reservoir cap.
- Remove the front noise insulation.
- Place the (VAS 6208) under the engine.
- Remove the drain plug - 1 - and drain the coolant.
• Ignore - 2 -.
Filling
• The cooling system is filled year year-round with a mixture of water and coolant additive. Mixture ratio.
• Only use coolant according to 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. 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 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. Coolant additive portion must be at least 40%.
• If more freeze protection is needed due to the climate, increase the amount of coolant additive, but only up to 60% (freeze protection down to -40 °C (-40 °F)). Otherwise the freeze protection and cooling effectiveness will be reduced.
• Only use clean drinking water for mixing coolant.
• If the radiator, heat exchanger, cylinder head or head seal or cylinder block were replaced, do not reuse used coolant.
• Dirty coolant may not be used again.
• Use the refractometer (T10007) to determine the level of freeze protection in the coolant system.
Coolant Mixture Ratio
• Coolant (40%) and water (60%) for freeze protection down to -25 °C (-13 °F)
• Coolant (50%) and water (50%) for freeze protection down to -40 °C (-40 °F)
• Coolant, refer to the Parts Catalog
- Close the drain plug - 1 -.
- Fill coolant reservoir on (VAS 6096) with 10 liters of premixed coolant with the proper mixture ratio, for the mixture ratio.
- Attach (V.A.G 1274/8) to coolant reservoir.
- Install the (VAS 6096) on the (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 (87 to 145 psi) 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.
- Remove (VAS 6096) form (V.A.G 1274/8) on coolant reservoir.
- Connect the (V.A.G 1274/10) to the (V.A.G 1274/8).
- Unclip the plenum chamber cover - 2 - and remove it.
• Ignore - 1 and 3 - and the - arrow -.
- Loosen the coolant hose to the heat exchanger and pull it back until the connection no longer covers the bleeder hole in the coolant hose - arrow -.
- Fill the coolant until it escapes from the coolant hose bleeder hole.
- Slide the coolant hose onto the connection and secure with a spring clamp.
- If the vehicle has an auxiliary heater, switch it on for about 30 seconds.
- Close coolant reservoir cap.
- Start the engine.
- Adjust the temperature for all zones to "HI".
- Press the ECON button to turn off the Air Conditioning (A/C) compressor.
- Run the engine at 2000 RPM for 3 minutes.
- Run the engine at idle until both large coolant hoses on the radiator are warm.
- Run the engine at 2000 RPM for 2 minutes.
- Turn off engine and allow it to cool off.
- Install the front noise insulation.
Risk of scalding due to hot steam and hot coolant.
• The coolant system is under pressure when the engine is warm.
• Reduce pressure by covering coolant reservoir cap with a cloth and carefully opening.
- Check the coolant level.
• Coolant level must be at "MAX" marking with engine cold.
• Coolant level may be above "MAX" marking with engine at operating temperature.