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

• Engine is at operating temperature.

Test Sequence

Steam can be released when the cap is removed from the expansion tank. Cover the cap with a cloth and open carefully.

- 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) on 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 on 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 connection (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:

- Check for leaks inside the engine compartment and under the vehicle. Remove the noise insulation if necessary.

Pressure Relief Valve in Cap, Checking

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

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

- 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 maximum 1.4 bar using the hand pump on the cooling system tester.

The pressure relief valve must not open yet.

If the pressure relief valve opens prematurely:

- Replace the cap.

- Raise the pressure.

The pressure relief valve must open when the specified pressure is exceeded.

If the pressure relief valve does not open:

- Replace the cap.