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)

Conditions

• The engine is at operating temperature

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 cap on the coolant expansion tank.

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

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

- Connect the connector piece (V.A.G 1274 B/1) to the cooling system tester (V.A.G 1274 B) using the connecting hose.

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


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). To do this, 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 connecting piece (V.A.G 1274 B/1) onto the adapter (V.A.G 1274/9).

- Connect the connector piece (V.A.G 1274 B/1) to the cooling system tester (V.A.G 1274 B) using the connecting hose.

- Using the hand pump from the cooling system cooling system tester, build the maximum pressure to 1.4 bar.

The pressure relief valve must not open yet.

If the pressure relief valve opens prematurely:

- Replace the cap.

- Build the pressure to 1.4 bar.

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

If the pressure relief valve does not open:

- Replace the cap.