Cooling System, Checking For Leaks: Notes

WARNING: This page is about a different car, the 2022 Audi A6 Quattro and 2021 Audi A6 Quattro. However, it is still accessible from the selected car via links, so may be relevant.

Special tools and workshop equipment required

Cooling System Tester: VAG1274B
Cooling System Tester - Adapter: VAG1274/8
Cooling System Tester - Adapter: VAG1274/9 for version 2 cap
Adapter: VAG1274B/15 for version 1 cap

Procedure

Engine at operating temperature.
Ignition switched off.

CAUTION:

The cooling system is under pressure when the engine is warm. There is a risk of scalding due to hot steam and hot coolant.

Scalding the skin and other parts of the body is possible.

- Wear safety gloves.

- Wear protective eyewear.

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

-- Open the coolant expansion tank cap -1- by releasing the catch in direction of -arrow-.

Fig 1: Coolant Expansion Tank

Courtesy of AUDI OF AMERICA, LLC

-- Position the : VAG1274B with the : VAG1274/8 on the coolant expansion tank.

Fig 2: Identifying VAG1274B & VAG1274/8

Courtesy of AUDI OF AMERICA, LLC

-- Generate approximately 1 bar (14.5 psi) pressure using the cooling system tester hand pump.

The pressure must not drop more than 0.2 bar (2.9 psi) within 10 minutes.

-- If the pressure falls more than 0.2 bar (2.9 psi), search for leaks and correct the problem.

TIP:

The pressure decrease of 0.2 bar (2.9 psi) within 10 minutes is a condition of the cooling of the coolant. The colder the engine the more the pressure decrease. If necessary repeat the test with the engine cold.

CAUTION:

There is a risk of scalding due to hot steam and hot coolant.

Scalding the skin and other parts of the body is possible.

- Reducing the pressure: press the pressure release valve on the cooling system tester until the pressure gauge displays a value of 0.