13B-1
DIESEL INJECTION
Diesel injection: Precautions for repair
F9Q or K9K
13B
I - RISKS RELATING TO CONTAMINATION
The high-pressure direct injection system is highly sen-
sitive to contamination. The risks caused by contami-
nation are:
- damage to or destruction of the high pressure injec-
tion system,
-a component seizing,
-a component not being properly sealed.
All After-Sales operations must be performed under
very clean conditions. Having carried out an operation
in good conditions means that no impurities (particles a
few microns in size) have penetrated the system during
dismantling.
The cleanliness principle must be applied from the filter
to the injectors.
What are the sources of contamination?
- metal or plastic swarf,
- paint,
- fibres:
• cardboard,
• brushes,
• paper,
• clothing,
• cloth,
- foreign bodies such as hair,
- ambient air,
- etc.
1 - Cleaning cloths
Use lint free cleaning cloths (see Vehicle: Parts and
ingredients for the repairwork) .
The use of rags or ordinary paper towels is prohibited:
these produce lint and lose fibres, which then contami-
nate the fuel circuit.
Each cloth must only be used once.
2 - Blanking plugs
The blanking plugs are used to cap the fuel circuit once
it is opened and to therefore prevent contaminants
from entering.
A set of blanking plugs should be used once only and
used plugs must be discarded: once used, the plugs
are soiled and cleaning them is not sufficient to make
them reusable.
Unused plugs must also be discarded and must not be
used when carrying out work on an injection system.
Part number for set of blanking plugs: (see Vehicle:
Parts and ingredients for the repairwork) (04B, Con-
sumables - Products)
3 - Protective bags
Use hermetically-resealable plastic bags, using adhe-
sive tape, for example, to store components which will
be refitted and reused. Stored parts will therefore be
less subject to the risk of contamination.
These are single-use bags: after use they must be dis-
carded.
4 - Cleaning products
Two cleaning products can be used:
- an injector cleaner (see Vehicle: Parts and ingre-
dients for the repairwork) (04B, Consumables -
Products),
- an aerosol spray brake cleaner (see Vehicle: Parts
and ingredients for the repairwork) (04B, Consu-
mables - Products).
To use the injector cleaner, be sure to have a clean
brush in good condition (the brush must not lose any
bristles) as well as a clean container which has no im-
purities in it.
WARNING
Do not clean the engine with a high pressure clea-
ner to prevent damaging the connections.
Note:
There is no specific set of blanking plugs for S9U
and S9W engines. In order to comply with the
cleanliness recommendations, use plugs that are
compatible with the blanking plug sets for F9Q,
G9U, G9T or ZD3 engines.
Note:
Use a new injector cleaner each time work is car-
ried out (a used cleaning agent will contain impuri-
ties).
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