Coolant: Service and Repair
Cooling System, Draining and Filling
Special tools, testers and auxiliary items required
• Adapter (V.A.G 1274/8)
• Drip Tray For Workshop Crane (VAS 6208)
• Hose Clamp Pliers (V.A.G 1921)
• Cooling System Charge Unit (VAS 6096) with (VAS 6096/1)
• Refractometer (T10007)
Draining
• Drained coolant must be stored in a clean container for disposal or reuse.
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 opening.
- Open cap of coolant expansion tank.
- Remove center noise insulation fasteners - 1 to 3 -.
- Place (VAS 6208) under engine.
Vehicles with drain plug:
- Turn drain plug - arrow - on radiator left, place assisting hose on supports if necessary.
Vehicles without drain plug:
- Remove lower coolant hose - 2 - from radiator by removing retaining clamps.
• Ignore - 1 -.
All Vehicles
- Drain coolant.
- Also remove lower coolant hose to after-run coolant pump (V51) - arrow - and allow remaining coolant to drain.
Filling
• 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.
• Protection against frost must be assured to about -25 °C / -13 °F (in arctic climatic countries to about -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 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.
• 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 (T10007) to determine the level of freeze protection in the coolant system.
Vehicles with drain plug:
- Close the drain plug - arrow -.
Vehicles without drain plug:
- Connect lower coolant hose - 2 - to radiator.
• Ignore - 1 -.
All Vehicles
- Connect coolant hose to after-run coolant pump (V51) - arrow -.
• Shown in illustration on vehicle with Direct Shift Gearbox transmission.
- Fill (VAS 6096/1) with at least 10 liters of pre-mixed coolant with correct mixture ratio:
• G12+ (40%) and water (60%) for freeze protection down to -25 °C / -13 °F
• G12+ (50%) and water (50%) for freeze protection down to -35 °C / -31 °F
• G12+ (60%) and water (40%) for freeze protection down to -40 °C / -40 °F
- Install (V.A.G 1274/8) on expansion tank.
- Assemble (VAS 6096) on (V.A.G 1274/8).
- 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 (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 the instrument display must still remain in the green region.
- 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 region, repeat procedure.
If the 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 (VAS 6096/1); cooling system is filled.
- Check coolant level and add coolant up to max-marking.
- Start engine, allow it to run at approximately 1500 RPM for a max. of 2 minutes and fill coolant up to overflow hole of expansion tank.
- Seal coolant reservoir.
- Allow engine to run until fan turns on.
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 opening.
- Check coolant level, and top off, if necessary.
• When the engine is at normal operating temperature, the coolant level must be on the Max. mark, and when the engine is cold, between the Min. and Max. marks.
- Switch engine off.