Cooling System: Testing and Inspection

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)

Test Conditions

• Engine at operating temperature.

Test Sequence


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

- Open cap of coolant expansion tank.

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






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

- If pressure decreases, search for leaking areas and repair the malfunction.

Pressure Relief Valve in Cap, Checking

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






- Operate hand pump.

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