Cooling System, Checking For Coolant Leaks

WARNING: This page is about a different car, the 2008 Volkswagen Jetta, 2008 Volkswagen GLI, 2007 Volkswagen Jetta, and 2006 Volkswagen Jetta. However, it is still accessible from the selected car via links, so may be relevant.

Special tools and workshop equipment required

Cooling system tester VAG 1274
Adapter VAG 1274/8
Adapter VAG 1274/9

Test Sequence

Engine at operating temperature.

WARNING:

Hot steam may escape when opening the expansion tank cap. Wear protective goggles and protective clothing to prevent damage to your eyes and from scalding. Cover the cap with a cloth and open the cap very carefully.

-- Remove the coolant expansion tank cap.

-- Install the VAG 1274 with the VAG 1274/8 onto the expansion tank.

Fig 1: Identifying Cooling System Tester V.A.G 1274 And Adapter V.A.G 1274/8 Attached To Expansion Tank

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Generate a positive pressure of approximately 1.0 bar using the VAG 1274.

If the pressure drops:

-- Search for leaking areas and repair the malfunction.

Fig 2: Identifying Cooling System Tester V.A.G 1274 And Adapter V.A.G 1274/9 Attached To Sealing Cap

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Install the VAG 1274 with the VAG 1274/9 to the expansion tank cap.

-- Operate the VAG 1274.

The pressure release valve must open at 1.4 to 1.6 bar.