Cooling System: Testing and Inspection

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)

Test Conditions:

• The engine is at operating temperature.

Test Sequence:

The coolant system is under pressure when the engine is warm.

Risk of scalding due to hot steam and hot coolant.

Reduce pressure by covering the coolant expansion tank cap with a cloth and carefully opening.

- Open the coolant expansion tank cap.

- Install the adapter (V.A.G 1274/8) onto the coolant expansion tank.

- Clamp the connection (V.A.G 1274 B/1) onto the adapter (V.A.G 1274/8).

- Connect the connection (V.A.G 1274 B/1) to the coolant system tester (V.A.G 1274 B) using the hose provided.






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

Risk of scalding! Reduce the pressure before disconnecting the cooling system tester (V.A.G 1274 B) from the connecting hose or connector piece (V.A.G 1274 B/1). Press the pressure release valve on the cooling system tester (V.A.G 1274 B) until the pressure gauge displays "0".

If the pressure drops:

- Look for leaks and correct.

Checking the Pressure Relief Valve in the Cap:

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

- Clamp the connection (V.A.G 1274 B/1) to the adapter (V.A.G 1274/9).

- Connect the connection (V.A.G 1274 B/1) onto the coolant system tester (V.A.G 1274 B) using the hose provided.






- Build up pressure with the hand pump.

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

• If the pressure relief valve opens too early or too late:

• Replace the cap.