Test Sequence
-- 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 connector piece V.A.G 1274 B/1 to the cooling system tester V.A.G 1274 B using the connecting hose.
-- Generate a positive pressure of approximately 1.0 bar using the tester.
If the pressure drops:
-- Search for the leaking areas and repair the malfunction.
Checking the Pressure Relief Valve inside the Cap
-- Install the cap to the adapter V.A.G 1274/9.
-- Clamp the connecting piece V.A.G 1274 B/1 on the adapter V.A.G 1274/9.
-- Connect the connector piece V.A.G 1274 B/1 to the cooling system tester V.A.G 1274 B using the connecting hose.
-- 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.