radiator cap AUDI A4 1998 B5 / 1.G APB Engine Cooling System Components

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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19-22

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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19-25

- Start engine and let it idle for about 10
minutes.

- Maintain an engine speed of about 2000 RPM
for about 5 minutes.

- Allow engine to run at idling speed until bottom
hose on radiator becomes hot.

- Check coolant level and top up if necessary.
When engine is at normal operating temperature
coolant level must be on max. mark, and
between min. and max. marks when engine is
cold.

Note:
When the engine is hot the cooling system is
under pressure. Carefully open filler cap on
expansion tank to release pressure before
starting repair work.

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.
Pa
ge 27 of 34 Coolin
g system com
ponents, removin
g and installin
g
11/21/2002 htt
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yp
e=re
pair&id=AUDI.B5.GE05.19.1