Volkswagen Workshop Service and Repair Manuals

Checking charge air system for leaks Special tools and workshop equipment required

t  Charge air system tester -V.A.G 1687- t  Adapter -V.A.G 1687/5- –  Remove noise insulation → General body repairs, exterior; Rep. gr.50

–  Release clip -A- and detach hose -B- from charge air pipe.

–  Fit adapter -V.A.G 1687/5- onto charge air hose -A- and turn adapter through approx. 90° -B-. Prepare charge air system tester -V.A.G 1687- as follows:

–  Turn pressure regulating valve -2- anti-clockwise onto stop. –  Close valves -3- and -4-.   Note To turn the pressure regulating valve -2- the knob must be pulled upwards.

–  Connect charge air system tester -V.A.G 1687- as shown.

–  Connect compressed air hose -1- (compressed air source) to charge air system tester -V.A.G 1687-.   Note If there is water in the sight glass, drain at water drain screw -6-. –  Open valve -3-. –  Adjust pressure to 0.5 bar with pressure regulating valve -2-.   Caution The pressure must not exceed 0.5 bar! If the pressure is too high this can cause damage to the engine. –  Open valve -4- and wait until the test circuit is filled. If necessary readjust pressure to 0.5 bar. –  Check the charge air system for leaks by hearing, touching, with commercially available leak detector spray or using ultrasonic tester -V.A.G 1842-.   Note t  Fitting hose connections with plug-in connectors → Chapter t  A small amount of air escapes through the valves and enters the engine. Therefore a holding pressure test is not possible. t  How to use the ultrasonic tester -V.A.G 1842- → operating instructions t  Depressurise test circuit by detaching coupling from adapter -V.A.G 1687/5- before removing adapter. t  Hose connections and hoses for charge air system must be free of oil and grease before assembly.