Draining and filling cooling system — VW

🧭 Before you start

Open the expansion tank cap carefully, remove the noise insulation and drain the coolant from the radiator hose. Refit the hose, fill the charging unit with at least 10 litres of correctly mixed coolant, evacuate the system and let the vacuum draw the coolant in. Run the engine with the heater on HI and the compressor off, top up to the overflow and then to the upper mark, and warm up until the fan cuts in.

Fits: platform codes A32, A33

• Opens: coolant
• Special tools named: V.A.G 1274/8

Don't miss

• Open the expansion tank cap under a cloth; a warm system is pressurised and can scald.
• If the vacuum gauge needle does not reach the green zone, repeat; if vacuum drops, check for leaks.
• Use distilled water and only approved coolant additives when mixing.
• Catch the coolant carried out by the vent hose in a small container.
• Bleed with the heater on HI and the air conditioner compressor switched off.

Written for this job from the workshop steps below · TorqFix editorial.

🔧 Engine codes this applies to

📋 Procedure

1. ⚠ When the engine is warm, the cooling system is under pressure.Hot steam/hot coolant can escape - risk of scalding.Cover filler cap on coolant expansion tank with a cloth and open carefully to dissipate pressure. — Carefully open filler cap (1) on coolant expansion tank (2) in (direction of arrow).
2. Remove noise insulation General body repairs, exterior66Noise insulation; Assembly overview - noise insulation.
3. Place drip tray under radiator.
4. Open spring-type clip (1) and pull off coolant hose (2). [Note: The amount of water used in the coolant mixture has a great influence on its effectiveness. Because the water quality differs from country to country and even region to region, the quality of the water to be used has been defined. Distilled water fulfils all requirements. For this reason, we recommend using distilled water when mixing coolant for topping up or replacing coolant.Use only coolant additives which conform with the Electronic parts catalogue. Other coolant additives may reduce corrosion protection substantially. The resulting damage could lead to loss of coolant and subsequent severe damage to the engine.The correct coolant solution ratio helps prevent damage due to freezing and corrosion as well as scaling. Moreover, the boiling temperature is raised. Therefore, the cooling system must be filled all year round with coolant additive.Because of its high boiling point, the coolant improves engine reliability under heavy loads, particularly in countries with tropical climates.ONLY refractometer T10007A may be used for determining current anti-freeze value.Frost protection must be guaranteed down to -25°C as a minimum and, in countries with arctic conditions, down to approx. -36°C. Increasing the frost protection is permissible only if climatic conditions require stronger frost protection. But only to -48 °C. Otherwise, the cooling effect of the coolant will be impaired.The coolant concentration must not be reduced by adding water even in warmer seasons and in warmer countries. The frost protection must be at least -25 °C.Read off anti-freeze figures for respective replenished anti-freeze.The temperature read off the refractometer T10007A equates to the »ice flocculation point«. Flakes of ice can start forming in the coolant below this temperature.Do not reuse old coolant.Use only a water/anti-freeze mixture as a slip agent for coolant hoses.]
5. Fit coolant hose (2) onto cooler connection piece and secure it with spring-type clip (1).

6. Fill spare container for cooling system charge unitVAS 6096/1 of unit cooling system charge unitVAS 6096 with at least 10 litres of pre-mixed coolant in correct mixture ratio:
7. Use coolant with correct mixture ratio.
8. Screw adapter for cooling system testerV.A.G 1274/8 onto coolant expansion tank.
9. Install cooling system charge unitVAS 6096 to adapter V.A.G 1274/8.
10. Feed vent hose (1) into a small container (2). [Note: Exhaust air takes a slight quantity of coolant along with it; this should be collected.]
11. Close valves (A) and (B) (turn lever transverse to direction of flow to do this).
12. Connect hose (3) to compressed air.
13. Open valve (B); turn lever in direction of flow to do this.
14. Also, open valve (A) briefly.
15. To do this, turn lever in direction of flow so that hose of spare container for cooling system charge unitVAS 6096/1 is filled with coolant.
16. Close valve (A) again.
17. Leave valve (B) open for a further 2 minutes.
18. Close valve (B). [Note: If the needle does not reach the green zone, repeat the process.If the vacuum drops, the cooling system must be checked for leaks.]
19. Pull off compressed air hose.
20. Open valve (A).
21. Remove cooling system charge unitVAS 6096 from coolant expansion tank.
22. Fill coolant up to "“max.”" mark (arrow) on coolant expansion tank (1).
23. Install noise insulation General body repairs, exterior66Noise insulation; Assembly overview - noise insulation.
24. On vehicles with auxiliary heater switch on auxiliary heater for about 30 seconds.
25. Set temperature regulator to "“HI”".
26. Switch off air conditioner compressor. To do this, press AC button.
27. Start engine and run it for max. 2 min. at a speed of approx. 1500 rpm.
28. Fill coolant up to the overflow hole of the coolant expansion tank while the engine is running.
29. Tighten cap of coolant expansion tank until it engages.
30. Run engine at idling speed until both large coolant hoses on the radiator are heated up.
31. Switch off engine and let it cool off.
32. Check coolant level in coolant expansion tank (1).
33. Fill more coolant if necessary.
34. Slowly replenish coolant to upper marking of hatched field (arrow) on expansion tank.
35. Fit expansion tank cap.
36. Switch off heater and air conditioning.
37. Start engine and maintain engine speed at approx. 2000 rpm for approx. 3 minutes.
38. Run engine until fan cuts in.
39. ⚠ When the engine is warm, the cooling system is under pressure.Hot steam/hot coolant can escape - risk of scalding.Cover filler cap on coolant expansion tank with a cloth and open carefully to dissipate pressure. — Check coolant level with expansion tank closed and top up with coolant, if necessary, when engine has cooled down.

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