Checking the pressure relief valve in the coolant expansion tank cap
WARNING: This page is about a different car, the 2024 Audi A3 Quattro and 2024 Audi A3. However, it is still accessible from the selected car via links, so may be relevant.
-- Position the Cooling System Tester:V.A.G 1274B with the Cooling System Tester - Adapter :V.A.G 1274/9 on the cap (example illustration).
-- Generate pressure with the cooling system tester hand pump.
- The pressure release valve must open at 1.6 to 1.8 bar (23.21 to 26.11 psi).
-- If pressure relief valve does not open as specified, replace the cap.