coolant AUDI A4 1999 B5 / 1.G APB Engine Cooling System Components

19-14


Repair Manual, 2.7 Liter V6 5V BiTurbo Fuel
Injection & Ignition, Engine Code(s): APB, Repair Group 01
7 -
Right coolant line From turbocharger to rear coolant line
8 -
Banjo bolt Tightening torque: 35 Nm
9 -
Coolant temperature sender (-G62-) For engine control moduleIf necessary, release pressure in cooling
system before removing Checking:
10 -
Retaining clip
Check for proper seating
11 -
To heat exchanger
12 -
Rear coolant line Diagram of coolant hose connections
Page 19
-17

Pa
ge 15 of 34 Coolin
g system com
ponents, removin
g and installin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE05.19.1

19-15


13 -
Bolt
Tightening torque: 10 Nm
14 -
Right coolant line From engine block to turbocharger
15 -
Banjo bolt Tightening torque: 35 Nm
16 -
Banjo bolt Tightening torque: 35 Nm
17 -
Right coolant line From engine block to turbocharger
18 -
From heat exchanger
19 -
To front coolant hose
Pa
ge 16 of 34 Coolin
g system com
ponents, removin
g and installin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE05.19.1

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
Pa
ge 17 of 34 Coolin
g system com
ponents, removin
g and installin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE05.19.1

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
Pa
ge 18 of 34 Coolin
g system com
ponents, removin
g and installin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE05.19.1

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
Pa
ge 19 of 34 Coolin
g system com
ponents, removin
g and installin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE05.19.1

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.
Pa
ge 20 of 34 Coolin
g system com
ponents, removin
g and installin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE05.19.1

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.
Pa
ge 21 of 34 Coolin
g system com
ponents, removin
g and installin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE05.19.1

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.
Pa
ge 22 of 34 Coolin
g system com
ponents, removin
g and installin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE05.19.1

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
Pa
ge 23 of 34 Coolin
g system com
ponents, removin
g and installin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE05.19.1

19-23

- Replace O-ring on coolant drain screw and
screw drain screw back into engine.

Tightening torque: 20 Nm

- Install bottom coolant hose and secure.

- Close coolant drain tap on radiator.

- Screw adapter VAG 1274/8 onto expansion tank and insert extension
VAG 1274/10 into the adapter.

- Loosen coolant hose on heat exchanger and pull back hose far enough
so that bleeder hole in hose -arrow- is no longer covered by
connection.
- Fill up coolant until it comes out at bleeder hole in coolant hose.
- Push coolant hose onto connection and tighten.
Pa
ge 25 of 34 Coolin
g system com
ponents, removin
g and installin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE05.19.1