Audi Workshop Service and Repair Manuals

Checking fuel system for leaks - vehicles with 2.0 ltr. 4V 4-cylinder engine

Special tools and workshop equipment required

t	Hose clamps for hoses up to 25 mm Ø -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 (2x) -V.A.G 1318/17-1- from adapter set -V.A.G 1318/17-

t	Tandem pump tester -VAS 5187-

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

Procedure –  Pull off engine cover panel -arrows-.   WARNING t  The fuel system is pressurised. Before opening the system place a clean cloth around the connection. Then release pressure by carefully loosening the connection. t  In extreme cases the fuel lines and the fuel can reach a temperature of 100 °C on vehicles with unit injector engine. Allow the fuel to cool down before disconnecting the lines - danger of scalding. t  Wear protective gloves. t  Wear safety goggles.

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

–  Secure adapter for testing diesel fuel -V.A.G 1274/2- with adapter -V.A.G 1274/1A- to cooling system tester -V.A.G 1274-. –  Connect adapter for testing diesel fuel -V.A.G 1274/2- to tandem pump using banjo bolt from -VAS 5187-. Saloon: –  Detach trim in luggage compartment. –  If necessary, fold forward right backrest of rear seat bench. Avant: –  Remove left-side section of backrest (1/3 section) → Rep. Gr.72. –  Remove left-side trim in luggage compartment and anti-soiling tray → Rep. Gr.70.

All models: –  Unscrew cover for flange -arrows-.

–  Mark fuel supply pipe -1- and fuel return pipe -2-. –  Detach both pipes from flange (press release tabs).

–  Connect one adapter -V.A.G 1318/17-1- onto fuel supply pipe and one onto fuel return pipe. –  Clamp off adapter hoses using hose clamps -3094-.   Note The hose clamps -3094- must not be applied directly to the fuel pipes 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 the seal.