Checking cooling system for leaks

Special tools and workshop equipment required

• Adapter for cooling system tester - V.A.G 1274/8-
• Adapter for cooling system tester - V.A.G 1274/9-
• Cooling system tester - V.A.G 1274 B-

Self-test of cooling system tester - V.A.G 1274 B-

• Operate cooling system tester - V.A.G 1274 B- several times.

• Build up a pressure of 3.0 bar on cooling system tester.
• Observe pressure on pressure gauge of cooling system tester for 30 seconds.

If no pressure builds up or if the pressure drops again:

The cooling system tester - V.A.G 1274 B- is leaking and should not be used.

Checking cooling system for leaks

• Coolant temperature at least 40 °C

Skin and other parts of the body may be scalded.

• Wear protective gloves.
• Wear protective goggles.
• Reduce excess pressure by covering cap of coolant expansion tank with cloths and opening it carefully.

• Open cap -1- on coolant expansion tank.

• Fit cooling system tester - V.A.G 1274 B- with adapter - V.A.G 1274/8- to coolant expansion tank.
• Build up pressure of approx. 1.5 bar using hand pump of cooling system tester.

• The pressure must not drop by more than 0.2 bar within 10 minutes.

• If the pressure drops by more than 0.2 bar, locate and rectify leaks.

Skin and other parts of the body may be scalded.

• Release pressure by pressing pressure relief valve on cooling system tester until the gauge shows a pressure of 0.

Check pressure relief valve in cap.

• Fit cooling system tester - V.A.G 1274 B- with adapter - V.A.G 1274/9- onto coolant filler cap.
• Using hand pump of cooling system tester, build up pressure and check the opening pressure of the filler cap.

• Renew filler cap, if pressure relief valve does not open as described.