coolant AUDI A4 1997 B5 / 1.G AHA ATQ Engines Cooling System Components Owner's Manual

19-20

Coolant pump, removing and installing


Notes:

Always replace seals and gaskets.
Cover the toothed belt with a cloth to protect it
from coolant before removing the coolant pump.

Removing

- Remove front bumper.

Repair Manual, Body Exterior, Repair Group
63


- Move lock carrier into service position.

Repair Manual, Body Exterior, Repair Group
50


- Remove ribbed belt page 13
-8 .

- Remove toothed belt page 13
-12
.
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- Drain coolant page 19
-11
.
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19-21


- Remove the following components before removing coolant pump:
1 - Toothed belt tensioner roller
Tightening torque: 20 Nm (15 ft lb)
2 - Idler roller
Tightening torque: 45 Nm (33 ft lb)


- Remove coolant pump mounting bolts -1- and remove coolant pump -
2-.
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19-22

Installing
Installation is the reverse of removal, noting the
following:

- Remove any remaining sealant from sealing
surfaces of coolant pump and cylinder block.

- Clean sealing surfaces so they are completely
free of any oil or grease.

- Install new gasket on water pump flange.

- Install coolant pump -2- into cylinder block and tighten all 9 mounting
bolts (arrow -2-) to 10 Nm (7 ft lb).
- Install rear toothed belt guard on water pump housing (arrow -1-).
Tightening torque: 10 Nm (7 ft lb).
- Install and tension toothed belt page 13
-12
.
- Install toothed belt guard.
- Install ribbed belt page 13
-8 .
- Fill cooling system with coolant page 19
-11
.
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19-23

Thermostat, removing and installing


Notes:

Always replace seals and gaskets.
Cover the toothed belt with a cloth to protect it
from coolant before removing thermostat.

Removing

- Drain coolant page 19
-11
.

- Remove front bumper.

Repair Manual, Body Exterior, Repair Group
63


Lock carrier in service position

Repair Manual, Body Exterior, Repair Group
50


- Remove ribbed belt page 13
-8 .
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19-24

Installing
Installation is the reverse of removal, noting the
following:

Bleeder valve for thermostat (arrow) must be at the top.
- Install thermostat -4- into engine block.
- Moisten new O-ring -3- with coolant.

- Install connection -2- for thermostat and tighten bolt -1- to 10 Nm (7 ft
lb).
- Install and tension toothed belt page 13
-12
.
- Install ribbed belt page 13
-8 .
- Fill cooling system with coolant page 19
-11
.
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19-26

Coolant fan, checking


Test requirements

Test procedure
Fuse No. 34 OK Coolant Fan Control (FC) thermal switch -F18- OK
- Disconnect 3-pin harness connector from coolant Fan Control (FC)
thermal switch -F18- at bottom left of radiator.
- Switch ignition on.

- Bridge terminal -1- and terminal -2- of harness connector using
auxiliary cables from VW1594 connector test kit.
Coolant fan -V7- must run on 1st speed.
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19-27


If 1st or 2nd fan speed does not run:
Electrical Wiring Diagrams, Troubleshooting & Component Locations
If no open circuit can be found: - Bridge terminal -1- and terminal -3- of harness connector using
auxiliary cables from VW1594 connector test kit.
Coolant fan -V7- must run on 2nd speed.
- Locate and repair open circuit using wiring diagram:- Replace coolant fan -V7-.
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19-28

Cooling system, pressure test


Engine at operating temperature

WARNING!

The cooling system is pressurized when the
engine is warm. When opening the expansion
tank, wear gloves and other appropriate
protection, cover the cap with a cloth and
open carefully to relieve system pressure
slowly.

- Open cap on coolant expansion tank.

- Using VAG1274/8 adapter attach VAG1274 cooling system tester to
coolant expansion tank.
- Use tester hand pump to create a pressure of approx. 1.0 bar (14.5
psi).
- If pressure falls, check for leaks and repair.
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19-30


After-run coolant pump

1 -
Coolant reservoir
Perform coolant system leak test using
VAG1274 cooling system tester and
VAG1274/9 adapter.
2 -
Lower coolant pipe
3 -
25 Nm
4 -
25 Nm
5 -
Bracket for after-run coolant pump
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