Component Tests and General Diagnostics

Cooling System, Checking for Leaks

=> [ Checking with VAG 1274 ]

=> [ Checking with VAG 1274B ]

Checking with VAG 1274

Special tools, testers and auxiliary items required

• Cooling system tester (VAG 1274)

• Adapter (VAG 1274/8)

• Adapter (VAG 1274/9)

Conditions

• Engine at operating temperature

Sequence

CAUTION!
Hot steam may escape when opening the expansion tank cap. Wear protective goggles and protective clothing to prevent damage to eyes and scalding. Cover the cap with a cloth and open very carefully.

- Open the coolant expansion tank cap.

- Install the (VAG 1274/8) and the (VAG 1274) to the expansion tank.

- Generate a positive pressure of approximately 1.0 bar using the (VAG 1274).

If the pressure drops:

- Search for leaking areas and repair the malfunction.

Pressure Relief Valve in Cap, Checking

- Install the (VAG 1274/9) and the (VAG 1274) to the cap.





- Operate the (VAG 1274).

• 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.

Checking with VAG 1274B

Special tools, testers and auxiliary items required

• Cooling system tester (VAG 1274B)

• Adapter (VAG 1274/8)

• Adapter (VAG 1274/9)

Conditions

• Engine at operating temperature.

Sequence

CAUTION!
Hot steam may escape when opening the expansion tank cap. Wear protective goggles and protective clothing to prevent damage to eyes and scalding. Cover the cap with a cloth and open very carefully.

- Open the coolant expansion tank cap.

- Install the (VAG 1274/8) onto the expansion tank.

- Clamp the (VAG 1274B/1) in the (VAG 1274/8).

- Connect the (VAG 1274B/1) to the (VAG 1274B) using the connecting hose.





- Generate a positive pressure of approximately 1.0 bar using the (VAG 1274B).

CAUTION!
Risk of scalding! Reduce the pressure before disconnecting the (VAG 1274B) from the connecting hose or (VAG 1274B/1). To do this, press the pressure release valve on the (VAG 1274B) until the manometer displays 0.

If the pressure drops:

- Search for leaking areas and repair the malfunction.

Pressure Relief Valve in Cap, Checking

- Install the cap in the (VAG 1274/9).

- Clamp the (VAG 1274B/1) in the (VAG 1274/9).

- Connect the (VAG 1274B/1) to the (VAG 1274B) using the connecting hose.





- Actuate the (VAG 1274B).

• 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.