Pressure Relief Valve In Cap, Checking

WARNING: This page is about a different car, the 2008 Volkswagen R32. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Attaching Cooling System Tester V.A.G 1274 With Adapter V.A.G 1274/9 On Sealing Cap

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Install the VAG 1274 with the VAG 1274/9 on the cap.

-- Generate a positive pressure of maximum 1.4 bar using the VAG 1274.

Pressure relief valve must not open yet.

If pressure relief valve opens prematurely:

-- Replace the cap.

-- Increase the pressure to above 1.6 bar.

Pressure relief valve must open.

If the pressure relief valve does not open:

-- Replace the cap.