Cooling System: Testing and Inspection

Cooling system, pressure test

Special tools and equipment
- VAG1274 cooling system tester
- VAG1274/1 adapter or VAG1274/8 with VAG1274/9

Test condition:
- Engine at operating temperature

WARNING! The cooling system is pressurized when the engine is warm. When opening the expansion tank, wear gloves and other appropriate protection, cover the cap using a cloth, and open carefully to relieve system pressure slowly.

- Open coolant expansion tank cap.




Vehicles with small cap
- Using VAG1274/1 adapter, attach VAG1274 cooling system tester to coolant expansion tank.




Vehicles with large cap
- Using VAG1274/8 adapter, attach VAG1274 cooling system tester to coolant expansion tank.

All models
- Use tester hand pump to create approximately 1.0 bar (14.5 psi) pressure.
- If pressure drops, check for leaks and repair.

Pressure relief valve in cap, checking
Vehicles with small cap




- Using VAG1274/1 adapter (2 parts), attach VAG1274 cooling system tester to coolant expansion tank cap.
- Pump using hand pump.
Pressure relief valve must open at 1.2 - 1.5 bar (17.4 - 21.75 psi).




Vehicles with large cap
- Using VAG1274/9 adapter attach VAG1274 cooling system tester to coolant expansion tank cap.
- Pump using hand pump.
Pressure relief valve must open at 1.4 - 1.6 bar (20.3 - 23.2 psi).