Component Tests and General Diagnostics

Cooling System, Checking for Leaks

Special tools, testers and auxiliary items required

• Cooling System Tester (V.A.G 1274 B)

• Adapter (V.A.G 1274/8)

• Adapter (V.A.G 1274/9)

Procedure

• Engine at operating temperature.

CAUTION!
Cover cap of expansion tank with rag and open carefully, as hot steam for example hot coolant may escape when opening.

- Open cap of coolant expansion tank.

- Position Cooling System Tester (V.A.G 1274 B) with Adapter (V.A.G 1274/8) on expansion tank.





- Generate a positive pressure of approximately 1.0 bar using hand pump of cooling system tester.

If the pressure drops:

- Search for leaking areas and repair the malfunction.

Pressure relief valve in cap, checking





- Position Cooling System Tester (V.A.G 1274 B) with Adapter (V.A.G 1274/9) on cap.

- Generate a positive pressure using hand pump of cooling system tester.

• The pressure release valve must open at 1.4 to 1.6 bar.

If check-valve does not open as indicated:

- Replace cap.