Volkswagen Workshop Service and Repair Manuals

Checking cooling system for leaks Special tools and workshop equipment required

t  Cooling system tester -V.A.G 1274 B-

t  Adapter for cooling system tester -V.A.G 1274/8-

t  Adapter for cooling system tester -V.A.G 1274/9-

Procedure l  Engine at operating temperature.   WARNING Hot steam/hot coolant can escape - risk of scalding. t  The cooling system is under pressure when the engine is hot. t  Cover filler cap on expansion tank with a cloth and open carefully to dissipate pressure. –  Open filler cap on expansion tank.

–  Fit cooling system tester -V.A.G 1274 B- with adapter -V.A.G 1274/8- on coolant expansion tank. –  Build up pressure of approx. 1.0 bar using hand pump of cooling system tester. –  If this pressure is not maintained, locate and rectify leaks.

Check pressure relief valve in cap. –  Place cooling system tester -V.A.G 1274 B- with adapter -V.A.G 1274/9- on filler cap. –  Build up pressure using hand pump of cooling system tester. l  The pressure relief valve should open at a pressure of 1.4 …1.6 bar. –  Renew filler cap, if pressure relief valve does not open as described.