cooling AUDI A4 1999 B5 / 1.G AFC Engine Cooling System Components

19-3


Cooling system, components Note:

Always replace gaskets and seals.
Draining and filling system with coolant page 19
-6 .
Testing cooling system for leaks page 19
-11
.
1 -
Thermostat
Replacing page 19
-4
Opening and closing temperatures page 19
-4
2 -
Seal
Always replace
3 -
Thermostat housing
4 -
10 Nm (7 ft lb)
5 -
Gasket Always replace
6 -
Coolant pump To remove and install, remove ribbed drive
belt ( page 13
-9 ) and toothed belt (
page 13
-11
)
7 -
10 Nm (7 ft lb)
Pa
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19-6

Cooling system, draining and filling


Note:

The cooling system is filled year round with a
mixture of water and anti-freeze and anti-
corrosion agent G 011 A8C.
G 011 A8C and coolant additives marked with
"conforming to TLVW 774 C" prevents freezing,
corrosion damage and scale formation, and
raises the coolant boiling point. For these
reasons the cooling system must always be
filled year-round with G 011 A8C anti-freeze
and anti-corrosion agent.
Due to its high boiling point, coolant is an aid to
operational efficiency when the engine is
operating at full load, particularly in tropical
climates.
Coolant must be drained and replaced if either
the radiator, heater core, cylinder head or
cylinder head gasket have been replaced.
Capacity: approx. 8.5 liters (9 qt.)

Draining

WARNING!
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The cooling system is pressurized when the
engine is warm. Wear gloves and other
appropriate protection, and slowly and
carefully release system pressure, if
necessary, before performing repairs.
Pa
ge 5 of 12 Coolin
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19-8


Filling
Recommended mixing ratios: 1) Do not exceed an antifreeze concentration of 60%; antifreeze protection
and cooling efficiency are reduced if the concentration is higher. 2) The quantity of coolant may differ depending on specific equipment
installed in the vehicle. - Using special tool 3247, drain coolant from engine drain plug (arrow)
and at drain plug on bottom left of radiator. Anti-freeze protection
down to: Anti-freeze
concentration
1) G 11
2)
Water
2)
-25 C (-13 F)
40% 2.5
liter
(2.6
qt.) 3.5 liter
(3.7 qt.)
-35 C (-31 F) 50% 3.0
liter
(3.2
qt.) 3.0 liter
(3.2 qt.)
Pa
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19-10

WARNING!

The cooling system is pressurized when the
engine is warm. Wear gloves and other
appropriate protection, and slowly and
carefully release system pressure, if
necessary, before performing repairs.

- Check coolant level in expansion tank and top
up if necessary.

- Stop engine (switch ignition off).
Pa
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19-11

Cooling system leaks, checking


WARNING!

The cooling system is pressurized when the
engine is warm. Wear gloves and other
appropriate protection, and slowly and
carefully release system pressure, if
necessary, before performing repairs.

Engine must be at operating temperature

If the pressure drops: - Connect cooling system tester VW 1274 to expansion tank using
adapter VW 1274/1.
- Operate hand pump on tester to create a pressure of approx. 1 bar (15
psi).
- Locate and repair leak in the cooling system.
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19-12

Expansion tank cap, pressure testing


- Screw cap onto cooling system tester VW 1274 with adapter VW
1274/1.
- Operate hand pump to build pressure.
- Pressure relief valve must open at 1.2-1.5 bar (17-22 psi).
Pa
ge 12 of 12 Coolin
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