Pressure Relief Valve in Cap, Checking
WARNING: This page is about a different car, the 2022 Volkswagen ID.4 and 2021 Volkswagen ID.4. However, it is still accessible from the selected car via links, so may be relevant.
Condition
- Check for leaks using Cooling System Tester: V.A.G 1274B .
CAUTION:
The cooling system can be under pressure. Risk of scalding by hot steam and hot coolant.
Possibility of scalding the skin and other parts of the body.
- Wear safety gloves.
- Wear protective eyewear.
- Reduce the pressure: cover the coolant expansion tank cap with a suitable towel and carefully open.
-- Open the caps -arrow-.
-- Connect the Cooling System Tester: V.A.G 1274B -1- and Cooling System Tester - Adapter: V.A.G 1274/9 -2- with the cap -3-.
-- Operate the hand pump -1- multiple times and create a pressure.
Condition
- Blue cap: at a pressure of 1.4 to 1.6 bar (20.31 to 23.21 psi) the pressure relief valve must open.
- Black cap: at a pressure of 1.6 to 1.8 bar (23.21 to 26.11 psi) the pressure relief valve must open.
-- If the pressure relief valve does not open as shown, replace the cap -3-.