1997 AUDI A4 APB Engine Cooling System Components

19-16


20 -
Coolant line
Diagram of coolant hose connections
Page 19
-17

21 -
Bleeder screw
Tightening torque: 20 Nm
22 -
Banjo bolt Tightening torque: 35 Nm
23 -
Left coolant line From turbocharger to rear coolant line
24 -
Sender for auxiliary water pump 2-pinIf necessary, release pressure in cooling
system before removing
25 -
To oil cooler
26 -
Retaining clip Check for proper seating
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19-17


Coolant hose connections, diagram

1 -
Bottom coolant hose
From radiator to engine
2 -
Cylinder head/ cylinder block
3 -
Right turbocharger
4 -
Auxiliary water pump
5 -
Heat exchanger for heater system
6 -
Coolant hose To heat exchanger
7 -
Left turbocharger
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19-18


8 -
Rear coolant line
9 -
Cap for expansion tank
10 -
Expansion tank
11 -
Oil cooler
12 -
Radiator
Removing and installing Page 19
-26
After replacing, replace coolant in complete
system
13 -
Coolant pump
14 -
Connection For thermostat
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19-19

Cooling system, draining and filling


Draining

WARNING!

Hot steam can escape from the expansion
tank when the filler cap is opened. Cover the
filler cap with a cloth and remove it carefully.

- Remove filler cap on coolant expansion tank.

- Remove noise insulation panel.
- Place drip tray VAG 1306 under the engine.

- If bumper has been removed from vehicle, open drain tap -arrow- on
bottom of radiator (left side) by turning anti-clockwise. Fit drain hose on
connection if necessary.
- If bumper has not been removed from vehicle, pull out retaining clip on
bottom hose going from radiator to engine (right side), and pull hose off
radiator.
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19-20


Note:
Observe disposal regulations for coolant.
Filling
Notes: - Drain coolant from engine at drain screw -arrow-.
Use only coolant additive G 12 - meeting specification VW 774 D.
Identification: colored red. G 12 must not be mixed with any other additives. If the fluid in the expansion tank is brown, this is an indication that G
12 has been mixed with another type of coolant. In this case the
coolant must be changed.
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19-21

G 12 and coolant additives complying with
specification "VW 774 D" prevent frost and
corrosion damage, scaling and also raise the
boiling point of the coolant. For this reason the
system must be filled all year round with the
correct additive for frost and corrosion
protection.
Particularly in countries with tropical climates,
the higher boiling point of the coolant improves
engine reliability when working under heavy
load.
The system must be protected against frost to
about -25 C (in arctic climates to about -35
C).

Use special tool T40007 to test coolant concentration and antifreeze
protection.
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19-22

The coolant concentration should not be
reduced by adding plain water, even in warmer
seasons and in warmer countries. The
concentration must be at least 40 %.
If extra antifreeze protection is required in cold
climates, the concentration of G 12 can be
increased, but only up to a maximum of 60 %
(frost protection to about -40 C); if this
concentration is exceeded, the antifreeze
protection will be reduced again and cooling
effectiveness will also be impaired.

Do not reuse the old coolant if the radiator, heat
exchanger, cylinder head or cylinder head
gasket have been replaced.
Recommended mixture ratios:

Frost
protection
to Antifreeze
concentration G
12
1) Water
1)
-25 C
-35 C
40 %
50 % 2.5
ltr.
3.0
ltr. 3.5 ltr.
3.0 ltr.

1) The capacity of the cooling system can vary
depending on the equipment installed on the
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vehicle.
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