Engine Coolant System, Checking For Leaks, High Temperature: Procedure:

WARNING: This page is about a different car, the 2014 Volkswagen Touareg, 2013 Volkswagen Touareg, 2012 Volkswagen Touareg, and 2011 Volkswagen Touareg. However, it is still accessible from the selected car via links, so may be relevant.

Engine at operating temperature.

WARNING:

Risk of scalding due to hot steam and hot coolant.

The coolant system is under pressure when the engine is warm.
Reduce pressure by covering the coolant reservoir cap with a cloth and carefully opening.

-- Open the coolant reservoir cap.

-- Position the Cooling System Tester:VAG1274B with the Cooling System Tester - Adapter:VAG1274/8 on the coolant reservoir.

Fig 1: Identifying V.A.G 1274 B With Adapter V.A.G 1274/8

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Generate approximately 1.5 bar (21.75 psi) pressure using the cooling system tester hand pump.

The pressure must not drop more than 0.2 bar (2.9 psi) within 10 minutes.

-- If the pressure falls more than 0.2 bar (2.9 psi), search for leaks and correct the problem.

NOTE:

The pressure decrease of 0.2 bar (2.9 psi) within 10 minutes is a condition of the cooling of the coolant. The colder the engine the more the pressure decrease. If necessary repeat the test with the engine cold.

CAUTION:

Risk of scalding! The existing pressure must be reduced before disconnecting the Cooling System Tester:VAG1274B from the connecting hose or the Adapter:VAG1274B/1 . To do this, press the pressure release valve on the Cooling System Tester:VAG1274B until the pressure gauge displays >>0<<.