Cooling System, Checking For Leaks

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 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 cap on the coolant expansion tank.

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

- Clamp the (V.A.G 1274 B/1) in the (V.A.G 1274/8).

- Connect the (V.A.G 1274 B/1) to the (V.A.G 1274 B) using the connecting hose.





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


Risk of scalding! Reduce the pressure before disconnecting the (V.A.G 1274 B) from the connecting hose or (V.A.G 1274 B/1). To do this, press the pressure release valve on the (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 (V.A.G 1274/9).

- Clamp the (V.A.G 1274 B/1) in the (V.A.G 1274/9).

- Connect the (V.A.G 1274 B/1) to the (V.A.G 1274 B) using the connecting hose.





- Actuate the (V.A.G 1274 B).

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