Component Tests and General Diagnostics

Cooling System, Checking for Leaks

Special tools, testers and auxiliary items required

• Cooling System Tester (V.A.G 1274)

• Adapter (V.A.G 1274/8)

• Adapter (V.A.G 1274/9)

Conditions

• Engine at operating temperature.

Sequence

CAUTION!
Hot steam may escape when opening the expansion tank cap. Wear protective goggles and protective clothing to prevent damage to eyes and scalding. Cover the cap with a cloth and open very carefully.

- Open the coolant expansion tank cap.

- Install the (V.A.G 1274) with (V.A.G 1274/8) to the expansion tank.





- Operate the (V.A.G 1274) and generate a positive pressure of 1.4 to 1.6 bar.

- Check the system for leaks.

If the pressure drops:

- Search for leaking areas and repair the malfunction.

Also check the cap.

- Install the (V.A.G 1274) with (V.A.G 1274/9) to the cap.





- Generate a maximum positive pressure of 1.6 bar using (V.A.G 1274).

Pressure relief valve must not open yet.

If pressure relief valve opens prematurely:

- Replace the cap.

- Increase pressure to above 1.6 bar.

Pressure relief valve must open.

If pressure relief valve does not open:

- Replace the cap.