Cooling System: Service and Repair
Coolant, Draining and Filling
Special tools, testers and auxiliary items required
• Adapter (V.A.G 1274/8)
• Adapter (V.A.G 1274/10)
• Cooling System Charge Unit (VAS 6096)
• Drip Tray for VAS 6100 (VAS 6208)
• Hose Clip Pliers (VAS 6362)
• 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.
- Remove the front noise insulation - 1 -.
- Place (VAS 6208) under the engine.
- Remove the drain plug - arrow - on the front coolant hose and drain the coolant.
- Remove the drain plug - arrow - on the map controlled engine cooling thermostat (F265) and drain the coolant.
Filling
• Tightening specifications, refer to => [ Coolant Pump and Coolant Thermostat Overview ] Coolant Pump and Coolant Thermostat Overview, => [ Coolant Pipes Overview ] Coolant Pipes Overview.
• Ignition turned off
• The cooling system is filled year-round with a mixture of water and coolant additive. Mixture ratio.
• Only use coolant according to the Electronic Parts Catalog (ETKA). 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. The coolant additive portion must be at least 40%.
• If for climatic reasons a greater frost protection is required, the amount of can be increased, but only up to 60% (frost protection to about -40 °C (-40 °F)), as otherwise frost protection is reduced again and cooling effectiveness is also reduced.
• Only use clean drinking water for mixing coolant.
• Only reuse drained coolant if the radiator, heater heat exchanger, cylinder head, cylinder head gasket or cylinder block were not replaced.
• Dirty coolant may not be used again.
• Use the (T10007) to determine the level of freeze protection in the coolant system.
• Secure all hose connections with hose clamps of the same type as those equipped by the factory. Refer to the Electronic Parts Catalog (ETKA).
• Replace the gasket and O-ring.
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 -35 °C (-31 °F)
• For the correct coolant, refer to the Electronic Parts Catalog (ETKA)
Procedure
- Install the drain plug - arrow - with a new O-ring on the map controlled engine cooling thermostat (F265).
- Install the front coolant pipe drain plug - arrow - with a new sealing.
- Fill coolant reservoir on (VAS 6096) with 15 liters of premixed coolant with the proper 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 the 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 instrument display must remain in the green region, then 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).
- Remove the center piece - 2 - or the entire plenum chamber cover, depending on the version.
- 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 the cap on the coolant reservoir until it latches.
- Start the engine.
- Adjust the temperature for all zones to "HI".
- 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 engine at 2000 RPM for 1 minute.
- Turn off the engine and allow it to cool off.
- Install the front noise insulation.
- Check the coolant level.
• With engine cold, coolant level must be at MAX marking.
• Coolant level may be above MAX marking with engine at operating temperature.