SEAT Workshop Service and Repair Manuals

Checking residual pressure –  Observe safety precautions → Chapter. –  Observe rules for cleanliness → Chapter.   WARNING Fuel supply line is pressurised. Wear eye protection and protective clothing to avoid eye injuries and skin contact. Before loosening hose connections, wrap a cloth around the connection. Then release pressure by carefully pulling hose off connection.

–  Disconnect supply line -1- (black) and catch escaping fuel with a cloth. Separate push-on couplings → Chapter.

l  Fuel pressure OK and pressure tester -VAS 6550- is connected to separating point in motor compartment. Check fuel pressure → Chapter. l  VAS 6550/1 between fuel line leading to engine and shut-off tap -B- l  VAS 6550/2 between fuel line leading to fuel tank and shut-off tap -A - Checking process: –  Actuate fuel pump with final control diagnosis to build up fuel pressure. –  Read off fuel pressure on pressure gauge. l  Specification: 3.0…3.2 bar –  Observe pressure drop on pressure gauge. After 10 minutes the pressure must not drop below 2.5 bar. If the pressure drops further: –  Actuate fuel pump with final control diagnosis to build up fuel pressure.

–  After pressure has built up, cut-off tap -B- of pressure tester immediately. Lever is then at right angle to direction of flow. If the pressure does not drop now:   Note Search for leak on engine side. Repeat holding pressure check. This time, close shut-off tap -A- to check whether leak actually is on engine side. –  Use an injector to check fuel line, fuel rail for leaks → Rep. gr.24. If the pressure drops again: Leak must be sought on fuel tank side; proceed as follows: Proceed as follows to check holding pressure at separating point on underbody:   WARNING Fuel supply line is pressurised. Wear eye protection and protective clothing to avoid eye injuries and skin contact. Before loosening hose connections, wrap a cloth around the connection. Then release pressure by carefully pulling hose off connection.

–  Disconnect fuel supply line -2-. Separate push-on couplings → Chapter.

–  Connect pressure tester -VAS 6550- with adapter -VAS 6550/1- and -VAS 6550/2- to push-on couplings of fuel supply line. t  VAS 6550/1 between fuel line leading to engine compartment and shut-off tap -B- t  VAS 6550/2 between fuel line leading to fuel tank and shut-off tap -A - –  Make sure that drain tap is closed and cut-off taps are open. –  Actuate fuel pump with final control diagnosis to build up fuel pressure.

–  After pressure has built up, cut-off tap -B- of pressure tester immediately. Lever is then at right angle to direction of flow. If the pressure does not drop now:   Note Check for leaks in the fuel line between separating point on underbody and separating point in motor compartment. If the pressure drops again: Proceed as follows to check holding pressure at fuel delivery unit: –  Remove bench seat → General body repairs, interior; Rep. gr.72.

–  Unclip cover -1- at retaining tabs -arrows-, using removal wedge -3409-.

–  Check that connector -1- is fitted securely by pulling connector without pressing catch. If connector was not inserted correctly, repeat functional check of fuel pump.   WARNING Fuel supply line is pressurised. Wear eye protection and protective clothing to avoid eye injuries and skin contact. Before loosening hose connections, wrap a cloth around the connection. Then release pressure by carefully pulling hose off connection. –  Disconnect fuel supply line -2- from fuel delivery unit. Separate push-on couplings → Chapter.

–  Connect pressure tester -VAS 6550- with adapter -VAS 6550/1- and -VAS 6550/2- between fuel supply line and fuel delivery unit. t  VAS 6550/1 between fuel line and shut-off tap -B- t  VAS 6550/2 between fuel delivery unit and shut-off tap -A-

–  Make sure that drain tap -C- is closed and cut-off taps -A- and -B- are open. –  Actuate fuel pump with final control diagnosis to build up fuel pressure. –  After pressure has built up, cut-off tap -B- of pressure tester immediately. Lever is then at right angle to direction of flow. If the pressure does not drop now:   Note Check for leaks in the fuel line between separating point on underbody and fuel delivery unit. If the pressure drops again: –  Renew fuel delivery unit → Chapter.