Checking fuel system for leaks

→ Ventilate the work area well.

→ Never ingest or inhale.

→ Read specific information on the Hazard Sheet.

→ Wear personal protective gear.

→ Do not smoke, eat or drink in the work area.

→ Avoid contact with hot parts or sources of ignition.

→ Use suction to remove ignitable vapors.

→ Attach warning sign in a clearly visible position.

→ Perform leak test.

1. Loosen hose clamp -2-  and remove fuel supply line -1-  from the fuel pipe -3-  . Absorb escaping fuel.

   Connection point for fuel supply line -1-  is located close to the torque support.

   Fuel supply line -1-  must not be damaged, otherwise fuel supply line -1-  must be replaced.

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   Information 

   • Check that the tool fittings are clean before starting the leak test  .
   • Clean the tool fittings before assembly using gentle bursts of compressed air to prevent dust and foreign bodies from getting into the high-pressure system during the leak test  .
   • Ensure that the tools for the leak test remain clean and free of dirt when stored  .
2. Fit adapter → Adapter VAG 1318/11  to the fuel supply line -1-  . Tighten hose clamp -2-  .

   The fuel supply line -1-  must not be damaged, otherwise the fuel supply line must be replaced.

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   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   NOTE: Test pressure is exceeded

   • Risk of damage to high-pressure pump

   → The test gas test pressure must be set to less than → Pressure: 10 bar  on the pressure reducer on the test gas bottle.

   WARNING: Working with compressed air

   • Risk of eye injuries
   • Risk of damaging and dirtying components

   → Wear protective goggles with side eye protection.

   → Protect the point at which the compressed air emerges with suitable material.

   → Place the point at which the compressed air emerges on suitable surfaces.

   Information 

   Unapproved test gases will give incorrect test results. Only the approved test gases guarantee comparability with fuel high-pressure systems at pressures of up to 10 bar  .

3. Fit test gas bottle with pressure reducer and air-spring strut filling unit VAS 6231 WE 1282  securely so that no gas can escape. Set pressure reducer to max. 10 bar pressure.

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   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

4. Air-spring strut filling unit VAS 6231 WE 1282  must then be connected to the adapter VAG1318/11. Tighten the connection -4-  if necessary.

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5. Depending on the high-pressure connections that were loosened (removed fuel distributor pipe or removed high-pressure pump), complete the following steps =>

   If the fuel distributor pipe (high-pressure rail) was removed =>

6. Before screwing the fuel distributor pipe (high-pressure rail) to the engine, quickly blow out residual fuel from the high-pressure pump and high-pressure line (intake) to the high-pressure rail.
   1. 6.1. Apply a quick burst of pressure using the filling unit and blow residual fuel out of the high-pressure pump and high-pressure line. Absorb escaping fuel.

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   2. 6.2. Drain residual fuel from the high-pressure distributor pipe before fitting it. Absorb escaping fuel.
7. Fit high-pressure distributor pipe (high-pressure rail) and tighten it to the correct tightening torques. → 243019 REMOVING AND INSTALLING FUEL DISTRIBUTOR PIPE (FUEL RAIL) ON DFI ENGINES
   NOTE: Test pressure is exceeded

   • Risk of damage to high-pressure pump

   → The test gas test pressure must be set to less than → Pressure: 10 bar  on the pressure reducer on the test gas bottle.

8. Use air-spring strut filling device VAS 6231 WE 1282  to apply test gas pressure of between 7 and just under 10 bar to the completely fitted high-pressure system. The pressure is distributed slowly in the system and can increase slightly on the pressure gauge → Building up pressure  . If there is a constant drop in pressure, there is a leak in the system.

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9. Spray all connection points in the high-pressure system with commercially available leak-locating spray. If the pressure drops even though the threaded joints are perfectly sealed, also spray the soldered joints and connecting pipes as well as the high-pressure pump and test equipment with leak-locating spray.
10. If there is a leak, gently sashaying, moving and growing  air bubbles will emerge. These could be caused by a damaged seal, loose connections or incorrectly fitted union nuts, for example. The cause must be determined and corrected.

    If the high-pressure pump was removed =>

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11. Before screwing the high-pressure line (intake) to the high-pressure pump, residual fuel must be blown out of the high-pressure pump.
    1. 11.1. Apply a quick burst of pressure using the filling unit and blow any fuel out of the high-pressure pump. Absorb escaping fuel.

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12. Screw high-pressure line correctly to the high-pressure pump. → 246319 REMOVING AND INSTALLING DFI HIGH-PRESSURE PUMP
    NOTE: Test pressure is exceeded

    • Risk of damage to high-pressure pump

    → The test gas test pressure must be set to less than → Pressure: 10 bar  on the pressure reducer on the test gas bottle.

13. Use air-spring strut filling device VAS 6231 WE 1282  to apply test gas pressure of between 7 and just under 10 bar to the fitted high-pressure pump. The pressure is distributed slowly in the system and can increase slightly on the pressure gauge → Building up pressure  . If there is a constant drop in pressure, there is a leak in the system.

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14. Spray all connection points for the high-pressure pump with commercially available leak-locating spray. If the pressure drops even though the threaded joints are perfectly sealed, also spray other connection points as well as the high-pressure pump and test equipment with leak-locating spray.
15. If there is a leak, gently sashaying, moving and growing  air bubbles will emerge (union nut on injector is shown) → Leaks 

    These could be caused by a damaged seal, loose connections or incorrectly fitted union nuts, for example. The cause must be determined and corrected.

    Courtesy of PORSCHE CARS NORTH AMERICA, INC.