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 for cooling system tester V.A.G 1274/8
• Spring-type clip pliers VAS 5024A
• Drip tray V.A.G 1306 or drip tray for workshop crane VAS 6208
• Torque wrench 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 

• Cold engine

Test Sequence 

-- Remove noise insulation Removal and Installation .

-- Disconnect the supply and return line from the oil cooler using hose clamps 3094.

Fig 1: Remove The Hose Clamps

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Remove the hose clamps -arrows- using hose clamp pliers VAS 5024A.

-- Disconnect the coolant hoses from the oil cooler.

-- Mount the sealing cap -- -5- on the rear connecting piece on the oil cooler -4-.

Fig 2: Mount The Sealing Cap

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Mount the sealing cap -- -2- on the expansion tank vent connection -1-.

-- Secure the coolant hose -3- on the oil cooler and on the expansion tank.

-- Fill the expansion tank up to the "Max" mark.

-- Position the cooling system tester V.A.G 1274 together with the adapter V.A.G 1274/8 on the expansion tank.

-- Generate a positive pressure of approximately 1.6 bar using hand pump of tester.

-- Watch pressure drop on gauge. The pressure must not fall within 10 minutes.

If the pressure drops:

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

Installation is performed in the reverse order of removal, noting the following:

-- Check the coolant level; top off if necessary COOLING SYSTEM, DRAINING AND FILLING .