Checking The Pressure Relief Valve In The Version 1 Cap

Fig 1: Coolant Expansion Tank

-- Position the :VAG1274B  with the :VAG1274B/15  on the cap.

-- Generate approximately 2 bar (29 psi) pressure using the cooling system tester hand pump.

Blue Cap: 

• The pressure must lower to 1.4 to 1.6 bar (20.30 to 23.20 psi) and stay there.

-- If the pressure relief valve does not react as specified, replace the cap.

Black Cap: 

• The pressure must lower to 1.6 to 1.8 bar (23.2 to 26.1 psi) and stay there.

-- If the pressure relief valve does not react as specified, replace the cap.

Checking The Pressure Relief Valve In The Version 2 Cap: 

-- Position the :VAG1274B  with the :VAG1274/9  on the cap.

-- Generate pressure with the cooling system tester hand pump.

Blue Cap: 

• The pressure release valve must open at 1.4 to 1.6 bar (20.30 to 23.20 psi).

-- If the pressure relief valve does not react as specified, replace the cap.

Black Cap: 

• The pressure release valve must open at 1.6 to 1.8 bar (23.2 to 26.1 psi).

-- If the pressure relief valve does not react as specified, replace the cap.

Additional procedures depending on the model: COOLING SYSTEM, CHECKING FOR LEAKS  .