AUDI A4 1995 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)
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19-4

Thermostat, replacing


- Remove ribbed belt page 13
-9 .

- Adjusting tension of toothed belt page 13
-
13
.

- Unbolt thermostat housing and pull out from below toothed belt.

Installation position of thermostat. The vent valve must be installed facing
up (arrow).
Starts to open at approx. 87 C (189 F)End of opening approx. 102 C (216 F)Stroke: 8.0 mm (5/16 in.)
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19-5

Coolant fan control thermal switch,
checking

The coolant fan control thermal switch -F54- is
located in the lower left part of the radiator.
Terminal assignment
3-pin connector Switching temperature

On
Off
1 = 1st stage
92 - 97 C
(198 - 207 F)
approx. 84 C (183 F)
2 = 2nd stage
99 - 105 C
(210 - 221 F)
approx. 91 C (196 F)
3 = Battery positive voltage (B+)
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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.
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19-7

- Open the cap on the coolant expansion tank.

- Remove noise insulation panel below engine.

- Drain coolant at radiator.
- Remove locking plate for connection flange of coolant hose at bottom
of radiator, pull off connection flange.
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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.)
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19-9

- Close drain plug at engine block and at bottom
left of radiator.

- Push on connection flange of coolant hose at
bottom of radiator, and install locking element for
connection flange.

- Unscrew cap on expansion tank, screw on adapter VAG 1274/1, and
extend with 42mm diameter and 100 mm long auxiliary hose.

- Open hose clamp, pull back coolant hose sufficiently so that vent hole
is no longer concealed by connection.
- Open bleed screw at coolant pipe below expansion tank.
- Pour coolant into system until it flows out at bleeder hole, then tighten
screw to 15 Nm (11 ft lb).
- Pour in more coolant until it flows out at vent hole, then push on
coolant hose and tighten.
- Close cap on expansion tank and set heater controls to hot position.
- Start engine and run at about 2000 RPM for about 3 minutes.
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- Continue running engine at idle until radiator becomes hot at the
bottom connection.
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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).
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