Volkswagen Workshop Service and Repair Manuals > Golf Mk5 > Power unit | 4-cylinder diesel engine (1.9 l engine) | Engine cooling | Parts of cooling system

Checking engine oil cooler for leaks

Special tools and workshop equipment required

t	Refractometer -T10007-

t	Hose clamps up to 25 mm -3094-

t	Cooling system tester -V.A.G 1274-

t	Adapter for cooling system tester -V.A.G 1274/8-

t	Spring-type clip pliers -VAS 5024A-

t	Drip tray -VAS 6208-

Special tools and workshop equipment required

t	Torque wrench -V.A.G 1331-

Not illustrated:

t	Expansion tank -1K0 121 407 A- or -6Q0 121 407 A- or -1J0 121 407 B-

t	Plug -191 211 343-

t	Cap -1J0 121 324-

t	Coolant hose -251 265 056-

t	Screw clamp

Test prerequisite:

l	Engine cold

Test procedure

–	Remove noise insulation → General body repairs, exterior; Rep. gr.50.

–	Clamp supply line and return line off engine oil cooler using hose clips to Ø 25 mm -3094-.

–	Loosen spring-type clips -arrows- using spring-type clip pliers -VAS 5024A-.

Note

Collect escaping coolant with drip tray -VAS 6208-.

–	Pull coolant hoses off engine oil cooler.

–	Push sealing cap -5- to rear connection of engine oil cooler -4-.

–	Secure sealing plug -2- to breather connection of expansion tank -1-.

–	Secure coolant hose -3- to oil cooler and expansion tank.

–	Fill expansion tank up to „Max“ marking.

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

Use hand pump on tester to create a pressure of about 1.6 bar.

Watch pressure drop on pressure gauge. A pressure drop within 10 minutes is not permitted.

If pressure drops:

–	Renew engine oil cooler.

Assembly is carried out in the reverse order, note the following:

–	Check coolant level, if necessary replenish coolant.

Volkswagen Workshop Service and Repair Manuals