Cooling System, Checking For Leaks: Notes

WARNING: This page is about a different car, the 2022 Audi Q8, 2021 Audi Q8, 2020 Audi Q8, and 2019 Audi Q8. 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
Adapter:VAG1274B/15 , for version 1 cap
Cooling System Tester - Adapter:VAG1274/9 for version 2 cap

Procedure

Engine at operating temperature.

Preliminary work may be required depending on the model. Refer to COOLING SYSTEM, CHECKING FOR LEAKS .

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.

Fig 1: Coolant Expansion Tank

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

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

-- 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.