Oil Cooler, Checking For Leaks

Special tools and workshop equipment required 

• Refractometer T10007
• Hose Clamps Up to 25 mm Dia. 3094
• Cooling System Tester V.A.G 1274
• Adapter V.A.G 1274/8
• Hose Clip Pliers VAS 6362
• Drip Tray for VAS 6100 VAS 6208
• Torque Wrench (5-50 Nm) V.A.G 1331
• Expansion Tank -1K0 121 407 A bzw. 6Q0 121 407 A bzw. 1J0 121 407 B-
• Sealing Plugs -191 211 343-
• Sealing Cap -1J0 121 324-
• Coolant Hose -251 265 056-

Test Conditions 

• Engine must be cold.

Test Sequence 

-- Remove the noise insulation. Refer to Description and Operation .

-- Clamp off the coolant hoses from the oil cooler using the hose clamps up to 25 mm dia. 3094.

Fig 1: Identifying Hose Clamps 3094

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Loosen the hose clamps -arrows- using hose clip pliersVAS 6362.

-- Disconnect the coolant hoses from the oil cooler.

-- Install the cap -5- on the rear fitting of the oil cooler -4-.

Fig 2: Identifying Cooling System Tester V.A.G 1274 And Adapter V.A.G 1274/8

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Secure the sealing cap -2- on the expansion tank -1- fitting.

-- Install the coolant hose -3- to the oil cooler and the coolant reservoir.

-- Slowly fill the coolant up to the upper mark in the hatched area on the expansion tank.

Fig 3: Identifying Expansion Tank

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Install the cooling system tester V.A.G 1274 with adapter V.A.G 1274/8 to the expansion tank.

-- Generate a pressure of approximately 1.6 bar using the cooling system tester -V.A.G 1274-.

-- Watch the pressure decrease on the pressure gauge.

• The pressure must not fall within 10 minutes.

If the pressure drops:

-- Replace the oil cooler OIL FILTER BRACKET AND OIL COOLER OVERVIEW .

Install in reverse order of removal. When doing this note the following:

-- Check the coolant level; fill if necessary. Refer to DRAINING AND FILLING .