Cooling system, checking for leaks

WARNING: This page is about a different car, the 2006 Audi A8, 2005 Audi A8, and 2004 Audi A8. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Special Tools - Cooling System, Checking For Leaks

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Special tools, testers and auxiliary items required

Cooling system tester V.A.G 1274
Adapter for cooling system tester V.A.G 1274/8
Adapter for cooling system tester V.A.G 1274/9

Test requirements

Engine at operating temperature.

Test sequence

CAUTION: Cover cap of expansion tank with rag and open carefully, as hot steam i.e. hot coolant may escape when opening.

Open cap of coolant expansion tank.

Fig 2: Attaching Cooling System Tester V.A.G 1274 With Adapter V.A.G 1274/8 To Expansion Tank

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Attach cooling system tester V.A.G 1274 with adapter V.A.G 1274/8 to expansion tank.
Generate a positive pressure of approx. 1.0 bar using hand pump of cooling system tester.
If pressure decreases, search for leaking areas and repair malfunction.

Pressure relief valve in cap, checking

Fig 3: Attaching Cooling System Tester V.A.G 1274 With Adapter V.A.G 1274/9 To Cap

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Attach cooling system tester V.A.G 1274 with adapter V.A.G 1274/9 to cap.
Operate hand pump.

Pressure release valve must open at a positive pressure of 1.4 to 1.6 bar.