Cooling System, Checking For Coolant Leaks

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.