Cooling System, Checking For Coolant Leaks

WARNING: This page is about a different car, the 2010 Volkswagen Jetta, 2009 Volkswagen Jetta, 2009 Volkswagen GLI, 2008 Volkswagen Jetta, and 2008 Volkswagen GLI. However, it is still accessible from the selected car via links, so may be relevant.

Special tools and workshop equipment required

Cooling System Tester V.A.G 1274 B
Adapter V.A.G 1274/8
Adapter V.A.G 1274/9

Test Conditions:

Engine at operating temperature.

Test Sequence:

WARNING:

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

-- Open the coolant expansion tank cap.

-- Install the adapter V.A.G 1274/8 onto the coolant expansion tank.

-- Clamp the connecting piece V.A.G 1274 B/1 on the adapter V.A.G 1274/8.

-- Connect the connecting piece V.A.G 1274 B/1 to the cooling system tester V.A.G 1274 B using the supplied hose.

Fig 1: Identifying Cooling System Tester V.A.G 1274 Connected To Coolant Reservoir

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Generate a positive pressure of approximately 1.0 bar using the cooling system tester hand pump.

WARNING:

Risk of scalding! Reduce the pressure before disconnecting the cooling system tester V.A.G 1274 B from the connecting hose or the connector piece V.A.G 1274 B/1. To do this, press the pressure release valve on the cooling system tester V.A.G 1274 B until the manometer displays 0.

If the pressure drops:

-- Search for leaking areas and repair the malfunction.

Pressure Relief Valve in Cap, Checking

-- Install the cap to the adapter V.A.G 1274/9.

-- Clamp the connecting piece V.A.G 1274 B/1 to the adapter V.A.G 1274/9.

-- Connect the connecting piece V.A.G 1274 B/1 to the cooling system tester V.A.G 1274 B using the supplied hose.

Fig 2: Identifying Connector Piece V.A.G 1274 B/1 Connected To Cooling System Tester V.A.G 1274 B Using Connecting Hose

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Actuate the hand pump.

The relief valve must open at 1.4 to 1.6 bar.

If the pressure relief valve opens too early or too late:

-- Replace the cap.