Rules for maintaining cleanliness when working with the fuel system (BMW 5 Series E34)

When working with the fuel system, it is imperative to follow the following rules:

Before removing, thoroughly clean the connection points and their surroundings.

Place removed parts in a clean place and cover. Use film and paper, do not use rags with lint.

Open parts must be carefully covered or sealed if repairs are not made immediately.

Remove spare parts from packaging immediately before installation. Install only clean parts.

Do not install parts that were not in the packaging (for example, taken from a toolbox).

If possible, do not work with compressed air when the fuel system is open. If possible, do not move the vehicle.