fuel tank capacity AUDI A8 2003 D3 / 2.G Technical Features Manual

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The tubing system for the tank breather at the
filler pipe has been considerably simplified as
compared to the predecessor model. With the
exception of diesel vehicles, the pipe
connections have been converted to quick-
release couplings.
A new feature is the use of a 2-stage delivery
pump for each tank chamber in
separate reservoirs.
The fuel level is measured by two immersion
tube senders combined with two angle
senders.
Engine, Mechanics
SSP282_007
Fuel tank
The fuel tank capacity is approximately
90 litres.
The basic unit consists of two plasma-welded
stainless steel shells. There are no differences
between petrol and diesel engine versions.
The filler neck is a single piece and welded to
the basic unit. For reasons of crash safety, the
centre section of the filler neck takes the form
of a corrugated tube.
In crash situations, this section is subject to
defined deformation to prevent cracks and
fuel spillage.
To create the best possible ergonomic
conditions for the rear passengers in
combination with maximum luggage
compartment volume, the two tank
compartments are shallower than in the
predecessor model.
The additional expansion tank has been taken
out of the filler pipe and moved to the fuel
tank.
The switch from plastic to stainless steel
was necessary for compliance with
American LEV II legislation, which
demands a further significant reduction in
permissible emission levels.
Activated charcoal filter
Fuel filler neck
Tank
compartment
breather
Diagnostic
connection

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Engine, Mechanics
Function
The main functions of the float-type rollover
valve are as follows:
– Closing-off of pipe to filler neck in the
event of rollover
– Closing in dynamic driving mode
– Closing by rising of float in valve in the
event of a brief excess of fuel in the tank
due to sloshing
Closing-off of the pipe to the activated
charcoal filter stops fuel overflowing into it. Expansion tank
The expansion tank (capacity approx. 2 litres)
consists of a plastic housing clipped to the
upper shell of the tank.
The internal expansion tank houses a float-
type rollover valve and a small suction jet
pump which constantly pumps the tank empty
whilst driving.
SSP282_009
Inlet pipe
from tank filler neck
Float-type
rollover valve
Float-type shutoff valve Breather pipe
Suction jet pump
intake connection