Defender (1993+). Manual — part 36

COOLING

SYSTEM

COOLING SYSTEM

DRAIN AND FILL COOLING SYSTEM

Engine Protection

WARNING: Do not remove the radiator filler cap

To prevent corrosion of the aluminium engine parts

it

when the engine is hot because the cooling

is vital that the cooling system is filled with a solution

system is pressurized and personal scalding

of clean water and anti-freeze winter and summer.

could result.

Never

fill

or top-up with water only, always add

anti-freeze. Never use salt water otherwise corrosion

will

occur. In certain territories where the only

available water supply may have some salt content,
use only clean rainwater or distilled water, with
anti-freeze added.
Use only Universal anti-freeze or permanent type
ethylene base, without methanol containing,

a

suitable inhibitor for aluminium engine parts. Use one
part of anti-freeze to one part water. Anti-freeze
should be used even in climates where is it not
necessary as a corrosion

inhibitor.

No

other

corrosion inhibitor should be used. A concentration
of at least 50% should be maintained.
Anti-freeze can remain in the cooling system and

will

provide adequate protection for

two

years provided

that the specific gravity of the coolant is checked
before the onset

of

the second winter and topped-up

with new anti-freeze as required.
The specific gravity can be checked with a
hydrometer and a 50% concentration at

68°

F

(20°

C shouId read

1.075.

2.

Disconnect bottom hose and drain cooling

Land Rovers leaving the factory have the cooling

system. Connect hose after draining.

system filled with a

50%

anti-freeze mixture. This

3.

To drain the expansion tank remove it from

gives protection against frost down to minus

47°

C

the vehicle, empty. flush-out and refit. If

(minus 53° F ) .

necessary renew the expansion tank hose.

After the second winter the system should be

4.

Make up a solution

of anti-freeze and water in

drained and thoroughly flushed. Before adding new

a separate container in the concentration

anti-freeze examine all joints and renew defective

required. The cooling system capacity is

hoses

to make sure that the system is leak proof.

quoted in the data section. Therefore

to

allow

See SECTION

09

for protection quantities.

for topping up and

the

expansion tank make

up a quantity

in excess

of this quantity.

5. Although anti-freeze may not be required it

should

be used as an inhibitor see under

'Engine Protection'.

6.

Fill

the system through the radiator filler plug

until the coolant is just below the filler neck.

7.

Fit the plug but do not over tighten.

8.

Half fill the expansion tank with coolant and
secure the cap correctly.

1.

Remove the radiator filler plug.

COOLING

SYSTEM

To

Refit

9.

Clean the timing cover mating face and
ensure all trace

of

old gasket is removed.

10. Smear a small quantity of grease on both

sides of a new gasket and place

it

in position

on the timing cover.

11.

Clean the threads of the four long bolts that
penetrate the cylinder block and apply Loctite
572

to

the threads.

12.

Fit the water pump

to the engine and secure

with the retaining

bolts

and single stud that

also secures

the

alternator adjustment strap.

13.

Fit the bottom hose

to

the water pump and

radiator.

14.

Fit the fan cowl,

if

removed.

15.

Fit and tension the drive belt.

9.

Start and run the engine until normal

16.

Fit the fan and viscous coupling.

operating temperature is reached. Allow the
engine

to

cool

and check the levels in the

radiator and expansion tank and top up

if

necessary. Finally check all hose connections
for leaks.

REMOVING

WATER PUMP

NOTE: The following instructions cover the basic

vehicle without air conditioning and power

steering. It may therefore

be

necessary to

remove other items in order to gain access to the

water pump.

To Remove

1.

Disconnect the battery.

2. Disconnect the bottom hose from the radiator

to drain the cooling system.

3.

Using a cranked open-ended spanner, remove

17.

Fill the cooling system

with

the required

the fan and viscous coupling assembly, noting

concentration of recommended anti-freeze in

that it has a left-handed thread.

accordance with the instructions in this
section.

4.

If

necessary, remove the

fan

cowl.

5. Remove the fan drive belt.

18.

Connect the battery and run the engine while

6.

Remove

the

bottom hose

from

the water

checking for leaks.

7.

Release the alternator adjustment strap from

REMOVING THERMOSTAT

8. Remove the fourteen bolts and withdraw the

To Remove

ST3166M

pump.

the water pump stud.

water pump and gasket.

1.

Disconnect the battery and drain the cooling

NOTE:

Information relating to the inspection

of

system.

the water pump is contained in the engine

2. Remove any pipes, hoses, or other items that

overhaul section 12.

may inhibit access to the thermostat housing.

3.

Remove the thermostat cover and withdraw

the thermostat. Clean any deposits

from

the

housing and the cover.

COOLING SYSTEM

4.

The temperature at which the thermostat

7. Fit the thermostat cover using a new gasket.

should be fully open is stamped on the

Coat the threads

of

the retaining screws with

forward end of the thermostat. The following

Loctite

572

and tighten the screws evenly

to

method can be used

to

determine

if

the

the correct torque.

thermostat

is

satisfactory and suitable for

8. Connect all pipes and hoses and refill the

refitting.

cooling system in accordance with the

instructions in this section.

5.

Place the thermostat and a Centigrade

thermometer

in a laboratory beaker, or a

suitable alternative, half

full of water. Heat the

water and observe the temperature at which
the thermostat opens.

If

faulty, discard the

thermostat.

To Refit

6.

The thermostat has a small vent hole in which

is fitted a 'jiggle' pin

to keep the hole clear. Fit

the thermostat to the housing ensuring that
this vent is uppermost at the

12

o'clock

position.

If

fitted

in any other way, an air lock

could result in the water passages causing
overheating and coolant

loss from the system.

COOLING

SYSTEM

REMOVING RADIATOR

To Refit

To remove

12. Lower the radiator into position in the engine

compartment, ensuring that the

two

pegs at

1.

Disconnect the battery.

the bottom of the radiator locate

in the

2.

Drain the cooling system.

corresponding rubber pads in the cross

3.

Disconnect the expansion and overflow hoses

member brackets.

from the top of the radiator.

13.

Locate the cowling into the clips at the bottom

4.

Release radiator support bracket fixings and

of the radiator and secure it

to

the top with

detach brackets.

the four screws.

5. Slacken top hose clip, detach hose and place

14.

Secure the top of the radiator with the

two

aside.

brackets and bolts.

6.

Place a suitable container under the oil cooler

15.

Secure the top and bottom hoses.

hose connections.

16.

Connect the

oil

cooler hoses

to

the radiator.

7.

Disconnect

oil cooler hoses at cooler and

17.

Connect the expansion tank and overflow

place aside.

hoses. Ensure all hose clips are fully

8. Slacken bottom hose clip, detach hose and

tightened.

place aside.

18. Refill cooling system with correct coolant

9.

Remove the screws securing the cowling to

mixture.

the radiator.

10.

Lift the cowling out

of

the clips at the bottom

of

the radiator and push it back towards the

engine.

11.

Carefully

lift

the radiator out of the engine

compartment.

19. Check and

top up engine oil as necessary.