General Repair Instructions; Rules For Cleanliness; Checking For Leaks In The Fuel System - Audi A8 2003 Workshop Manual

Audi A8 2003 ➤
8-cylinder TDI engine (4.0 ltr. 4-valve common rail), mechanics - Edition 12.2013
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General repair instructions

⇒ "3.1 Rules for cleanliness", page 4
⇒ "3.2 Checking for leaks in the fuel system", page 4
⇒ "3.3 Foreign particles in engine", page 5
⇒ "3.4 Contact corrosion", page 5
⇒ "3.5 Routing and attachment of pipes, hoses and wiring", page
5
⇒ "3.6 Installing radiators and condensers", page 5
⇒ "3.7 Checking vacuum system", page 5
3.1

Rules for cleanliness

Even small amounts of dirt can cause malfunctions. For this rea‐
son, please observe the following rules when working on the fuel
supply system, injection system and turbocharger:
♦ Carefully clean connection points and the surrounding area
with engine cleaner or brake cleaner and dry thoroughly before
opening.
♦ Immediately seal open lines and connections with clean plugs,
for example from engine bung set - VAS 6122- .
♦ Do not remove sealing caps from components until immedi‐
ately prior to installation. Keep components that are to be re-
used in new, sealable plastic bags.
♦ Place parts that have been removed on a clean surface and
cover them over. Do not use fluffy cloths.
♦ Carefully cover or seal open components if repairs cannot be
carried out immediately.
♦ Only install clean components; replacement parts should only
be unpacked immediately prior to installation. Do not use parts
that have not been stored in the proper packaging (e.g. in tool
boxes etc.).
♦ When the system is open: Do not work with compressed air.
Do not move the vehicle unless absolutely necessary.
♦ Make sure that no fuel runs onto the fuel hoses. Should this
occur, the fuel hoses must be cleaned again immediately.
♦ Also ensure that no diesel fuel comes into contact with the
coolant hoses. Should this occur, the hoses must be cleaned
immediately. Damaged hoses must be renewed.
♦ Protect unplugged electrical connectors against dirt and mois‐
ture and make sure connections are dry when attaching.
3.2

Checking for leaks in the fuel system

– Start the engine and let it run at medium speed for a few mi‐
nutes.
– Switch off ignition.
– Check the entire fuel system for leaks.
– If leaks are found although the connections have been tight‐
ened to the correct torque, the relevant component must be
renewed.
– Then carry out a test drive with at least one full-power accel‐
eration.
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Rep. gr.00 - Technical data
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