LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Volkswagen >> 2025 >> Golf R Base >> Repair and Diagnosis >> External Pages >> Different car >> Section 18 (Cooling System) >> 19 Cooling System >> Cooling System/Coolant >> Cooling System, Checking For Leaks >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Cooling System, Checking For Leaks: Procedure

WARNING: This page is about a different car, the 2025 Audi S3 and 2025 Audi A3 Quattro. However, it is still accessible from the selected car via links, so may be relevant.

Check (self-test) Cooling System Tester :V.A.G 1274B 

Fig 1: Special Tool VAG1274B
GWWN20-11243Courtesy of AUDI OF AMERICA, LLC

-- Operate the Cooling System Tester :V.A.G 1274 B  multiple times.

-- Create a pressure of 3.0 bar (43.51 psi) on the cooling system tester.

GWWN20-11171Courtesy of AUDI OF AMERICA, LLC

-- Pay attention to the pressure on the pressure gauge of the Cooling System Tester :V.A.G 1274 B  for 30 seconds.

If pressure is not built up or if the pressure falls again:

Cooling System, Checking for Leaks

CAUTION:

The cooling system is under pressure when the engine is warm. There is a risk of scalding due to hot steam and hot coolant.

Scalding the skin and other parts of the body is possible.

- Wear safety gloves.

- Wear protective eyewear.

- Reduce the pressure by covering the coolant expansion tank cap with a cloth and carefully opening it.

-- Open the coolant reservoir cap -arrow-.

GWWE10-10210Courtesy of AUDI OF AMERICA, LLC

-- Position the Cooling System Tester :V.A.G 1274B  with the Cooling System Tester - Adapter :V.A.G 1274/8  on the coolant expansion tank.

Fig 2: Identifying VAG1274B & VAG1274/8
GWWA19-12246Courtesy of AUDI OF AMERICA, LLC

-- Generate approximately 1.5 bar (21.76 psi) pressure using the cooling system tester hand pump.

If the pressure falls more than 0.2 bar:

-- Check the engine and radiator for leaks and correct.

CAUTION:

There is a risk of scalding due to hot steam and hot coolant.

Scalding the skin and other parts of the body is possible.

- Reducing the pressure: press the pressure release valve on the cooling system tester until the pressure gauge displays a value of 0.