Cooling System: Service and Repair
Cooling System, Draining and Filling
Special tools, testers and auxiliary items required
• Adapter (V.A.G 1274/8)
• Adapter (V.A.G 1274/10)
• Hose Clip Pliers (V.A.G 1921)
• Cooling System Charge Unit (VAS 6096)
• Drip Tray (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.
• Cover the coolant reservoir cap with a cloth and then open it slowly to release the pressure in the system.
- Open the coolant reservoir cap.
- Remove the front noise insulation - 1 -..
- Place the (VAS 6208) under the engine.
- Remove the drain plug - 1 - and drain the coolant.
• Ignore - 2 -.
- Remove the coolant hose from the engine oil cooler by loosening the hose clamp - arrow - and letting the remaining coolant drain out.
Filling
• Ignition turned 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. Refer 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.
• 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 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 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 (-40 °F). 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, heat exchanger for the heater, cylinder head, cylinder head seal or cylinder block were replaced.
• If the coolant is contaminated.
• Dirty coolant may not be used again.
• Secure all hose connections with hose clamps of the same type as those equipped by the factory. Refer to the Parts Catalog
• Use the (T10007) to determine the level of freeze protection in the coolant system.
- Close the drain plug - 1 -.
• Ignore - 2 -.
- Install the coolant hose on the oil cooler - arrow -.
- Fill the coolant reservoir on (VAS 6096) with at least 12 liters of premixed coolant with the proper mixture ratio:
• Coolant freeze and corrosion protection additive (40%) and water (60%) for freeze protection up to -25° C (-13 °F).
• Coolant freeze and corrosion protection additive (50%) and water (50%) for freeze protection down to -35° C (-31 °F).
• For coolant freeze and corrosion protection additive, refer to the Parts Catalog.
- Attach (V.A.G 1274/8) to the 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 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 the green area.
- Briefly open valve - A - by turning lever in direction of flow so that hose on the (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 sufficient vacuum in the cooling system is obtained for the upcoming filling.
• If the 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 the (VAS 6096) form the (V.A.G 1274/8) on coolant reservoir.
- Connect the (V.A.G 1274/10) to the (V.A.G 1274/8).
- Fill with coolant until the coolant system tester tube is full. Fill again during the bleeding procedure if necessary.
- Remove the gasket - 3 -.
- Open the clips - 1 - and remove the plenum chamber cover - 2 -.
- Pull back the coolant hose for the heater heat exchanger in order to loosen the hose clamp.
- As soon as coolant starts to come out of the vent hole - arrow -, attach the coolant hose to the connection and tighten the clamp.
- If the vehicle has an auxiliary heater, switch it on for about 30 seconds.
- Close the cap on the coolant reservoir until it latches.
- Start the engine.
- Set the temperature to "HI" for all zones and set the fan speed as low as possible (0).
- Press the AC button to turn off the A/C compressor.
• The LED in the button must not come on.
- 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 noise insulation..
- Check the coolant level.
• With the engine cold, coolant level must be at MAX marking.
• Coolant level may be above MAX marking with engine at operating temperature.