Audi Workshop Service and Repair Manuals

Checking for leaks A leaking fuel system can cause: t  Foam build-up or air bubbles in the supply line t  Lack of power, misfiring t  Starting problems

Special tools and workshop equipment required

t	Hose clamps for hoses up to 25 mm -3094-

t	Cooling system tester -V.A.G 1274- with adapter -V.A.G 1274/1A- and adapter for testing diesel fuel -V.A.G 1274/2-

t	Adapter -V.A.G 1318/17-1- from adapter set -V.A.G 1318/17- (2 x)

t	Banjo bolt -VAS 5187/1A- from tandem pump tester -VAS 5187-

Procedure Observe safety precautions → Chapter. Observe rules for cleanliness → Chapter. Engine cover panel (version 1): –  Pull dipstick -1- out of guide tube. –  Lift engine cover panel at the sides -arrows 2- and pull off towards the front -arrow 3-. –  Re-insert dipstick in guide tube.

Engine cover panel (version 2): –  Lift off engine cover panel (outside -1- and inside -2-) by pulling up evenly.

All vehicles (continued): –  Pull cover off air duct (release clips on sides) -arrows-.

–  Unclip air duct at the bottom by releasing clips -arrows-. –  Detach air duct (bottom) together with air hose.

–  Unplug electrical connector -1- at air mass meter -G70-. –  Detach vent hose -3- and air hose -2-. –  Unscrew bolt -4- and remove air cleaner housing.   Note Illustration shows vehicle with 2.0 litre engine.   WARNING t  The fuel system is pressurised. Wrap a cloth around the connection before opening the system. Then release pressure by carefully loosening the connection. t  In extreme cases the temperature of the fuel lines and the fuel can be up to 100 °C after the engine is switched off. Allow the fuel to cool down before disconnecting the lines - danger of scalding. t  Wear protective gloves. t  Wear safety goggles.

Vehicles with 2-valve engine: –  Remove screw plug -arrow-.   Note Illustration shows tandem pump with engine removed from vehicle.

Vehicles with 4-valve engine: –  Remove screw plug -arrow-.   Note Illustration shows tandem pump with engine removed from vehicle.

All vehicles (continued): –  Attach adapter -V.A.G 1274/2- with adapter -V.A.G 1274/1A- to coolant system tester -V.A.G 1274-. –  Connect adapter -V.A.G 1274/2- to tandem pump using banjo bolt -VAS 5187/1A-.

–  Remove rear seat bench → Rep. gr.72. –  Unclip retaining tabs -arrows- for flange cover.

–  Disconnect fuel supply line -1- and fuel return line -2- by pressing release tabs.

–  Connect one adapter -V.A.G 1318/17-1- onto supply line and one onto return line. –  Clamp off adapters -V.A.G 1318/17-1- using hose clamps -3094-.   Note The hose clamps -3094- must not be applied directly to the fuel lines themselves as this can cause damage.

–  Use cooling system tester -V.A.G 1274- to create a pressure of between 1.0 ... 1.5 bar. –  If pressure drops constantly, locate leak and eliminate fault.   Note After removing pressure tester, tighten screw plug to 25 Nm. Renew seal.