Checking exhaust gas recirculation cooler for leaks

Special tools and workshop equipment required

• Charge air system tester - V.A.G 1687-
• Adapter - V.A.G 1687/11-
• Adapter - V.A.G 1687/15- for exhaust pipes of 60 mm and 65 mm in diameter
• Adapter - V.A.G 1687/16- for exhaust pipes of 55 mm in diameter

• Y-branch - VAS 691 005/1-
• Test adapter - VAS 691 005/5-

• Turbocharger tester - V.A.G 1397A-

Test specification:

• Coolant temperature must be at least 40 °C.

Connecting turbocharger tester - V.A.G 1397A- :

• Screw adapter - VAS 691 005/5- onto coolant expansion tank.
• Fit Y-branch - VAS 691 005/1- onto adapter - VAS 691 005/5-.
• Close valve -1- for connection »C«, and open valve -2- for connection »A«.
• Connect hose from connection »A« of Y-branch to connection »II« of turbocharger tester - V.A.G 1397A-.
• Set turbocharger tester - V.A.G 1397A- to switch position »II« (gauge pressure measurement), and switch it on. The setting »II« must be visible.

Connecting charge air system tester - V.A.G 1687- :

• If fitted, unclip wire to exhaust flap control unit -1-.
• Loosen clamp -2- on exhaust pipe, and push it towards rear.

• On vehicles without a tunnel cross-piece, use a tensioning strap -2- to tie up exhaust pipe -1-.

• Connect adapter - V.A.G 1687/11- with hose -A- to exhaust pipe (engine side). Secure hose with hose clips.

  Use hose -A- for exhaust pipes of 55 mm in diameter = hose - V.A.G 1687/16-.

  Use hose -A- for exhaust pipes of 60 mm and 65 mm in diameter = hose - V.A.G 1687/15-.

• Connect charge air system tester - V.A.G 1687- to adapter - V.A.G 1687/11-.

Prepare charge air system tester - V.A.G 1687- as follows:

• Completely unscrew pressure regulating valve -2-, close valves -3- and -4-.

• To turn pressure regulating valve -2-, rotary knob must be pulled upwards.

• Apply compressed air -1- to charge air system tester - V.A.G 1687-.

• Open valve -3-.
• Adjust pressure to 0.8 bar with pressure control valve -2-.
• Open valve -4- and wait until test circuit is full. If necessary, adjust pressure to 0.8 bar.

Reading turbocharger tester - V.A.G 1397A- :

• Observe turbocharger tester for approx. 5 minutes.
• The pressure indicated on the turbocharger tester must not exceed 0.025 bar.

• If the pressure on the turbocharger tester rises above 0.025 bar, compressed air is leaking from the exhaust side into the cooling system. The exhaust gas recirculation cooler has a leak. Renew exhaust gas recirculation cooler.

Cleaning Y-branch - VAS 691 005/1- :

• Insert cleaning nozzle -D- into hose on connection -A- of Y junction.
• Fit adapter - VAS 691 005/5- onto hose of connection -B-.
• Fit compressed air hose to connection -C-.
• Open shut-off taps, and blow out hose for approx. 15 seconds.