1996 LAND ROVER DEFENDER ECU

19FUEL SYSTEM
18
REPAIR EGR THROTTLE POSITION SENSOR
Service repair no - 17.45.08
Remove
1.Remove 2 screws securing throttle position
sensor mounting plate to injection pump.
2.Disconnect sensor multi-plug.
3.Remove sensor assembly.
Refit
4.Position sensor assembly on injection pump and
secure with screws.
5.Connect multi-plug.
6.Adjust sensor
See Adjustment, EGR throttle
sensor
EGR CONTROL UNIT
Service repair no - 17.45.07
Remove
1.Raise centre seat, or cubby box
See CHASSIS
AND BODY, Repair, Cubby box
to gain access
to EGR control unit harness.
2.Disconnect control unit multi-plug and remove
centre seat or cubby box.
3.Remove 4 screws and detach control unit from
seat or cubby box base.
Refit
4.Secure EGR control unit to base of centre seat
or cubby box.
5.Position centre seat or cubby box and connect
control unit multi-plug.
6.Fit centre seat, or cubby box.
See CHASSIS
AND BODY, Repair, Cubby box

26COOLING SYSTEM
2
DESCRIPTION AND OPERATION ENGINE (COOLANT) COOLING
Description
The 300Tdi engine uses a pressurised cooling system
and cross flow radiator which is supplied with coolant
from an expansion tank mounted on the RH side of
the engine compartment. A belt driven centrifugal
water pump, fitted to an auxiliary mounting assembly,pumps coolant to the engine crankcase, cylinder head
and vehicle heater unit.
An eleven bladed fan, incorporating a viscous
coupling, is driven by an independent pulley secured
to the front cover plate. The thermostat housing,
bolted to the front of the cylinder head, is fitted with a
vent valve that purges excessive air pressure and
coolant back to the expansion tank.
Engine coolant circulation (engine warm - thermostat open).
1.Radiator
2.Thermostat/housing
3.Radiator bottom hose
4.Viscous fan
5.Water pump
6.Radiator top hose
7.Heater return hose
8.Coolant supply hose9.By-pass hose
10.Radiator bleed (purge) hose
11.Thermostat housing bleed (purge) hose
12.'Y' piece ejector
13.Expansion tank
14.Heater rail
15.Heater unit
16.Heater feed hose

26COOLING SYSTEM
2
REPAIR FAN COWL
Service repair no - 26.25.11
Remove
1.Disconnect battery.
2.Drain coolant.
See Adjustment, Drain and
refill cooling system.
3.Slacken retaining clips and remove radiator top
hose.
4.Slacken retaining clip and remove top hose from
intercooler.
NOTE: On vehicles fitted with EGR system,
remove complete intercooler top hose
assembly.
5.Remove viscous coupling and fan
See Viscous coupling and fan.
6.Remove 2 nuts securing top of fan cowl.
7.Release expansion tank hose from clips at base
of fan cowl.
8.Lift and remove cowl .
NOTE: On vehicles fitted with air
conditioning, it will be necessary to
remove the cowl and viscous fan unit
together to enable clearance of the compressor.Refit
9.Position fan cowl.
10.Fit viscous fan unit.
See Viscous coupling
and fan
11.Fit expansion tank hose into fan cowl clips.
12.Secure top of fan cowl to radiator top cover.
13.Fit intercooler top hose.
14.Fit radiator top hose.
15.Refill cooling system.
See Adjustment, Drain
and refill cooling system
16.Reconnect battery.
FAN PULLEY
Service repair no - 26.25.04.
Remove
1.Disconnect battery.
2.Remove viscous fan unit.
See Viscous
coupling and fan
3.Remove drive belt.See ELECTRICAL, Repair,
Auxiliary drive belt
4.Unscrew 4 bolts and remove pulley from adaptor
boss.
Refit
5.Fit fan pulley to adaptor boss. Tighten bolts to
25
Nm (18 lbf/ft).
6.Fit drive belt.See ELECTRICAL, Repair,
Auxiliary drive belt
7.Fit viscous fan unit.See Viscous coupling
and fan
8.Reconnect battery.

COOLING SYSTEM
3
REPAIR WATER PUMP
Service repair no - 26.50.01
Remove
1.Disconnect battery.
2.Drain cooling system.
See Adjustment, Drain
and refill cooling system
3.Remove radiator top hose.
4.Remove intercooler top hose.
5.Slacken water pump and power steering pump
pulley retaining bolts.
6.Remove drive belt.
See ELECTRICAL, Repair,
Auxiliary drive belt
7.Unscrew flange nut and remove belt tensioner.
8.Remove oil filler cap and remove rocker cover
insulation.
9.Slacken retaining clip and disconnect hose at
heater rail.
10.Unscrew 3 bolts and remove water pump pulley.
11.Unscrew 3 bolts and remove power steering
pump pulley.
12.Remove 8 bolts securing water pump, noting
location of 3 through bolts into cylinder block.
13.Withdraw pump and gasket from auxiliary
mounting bracket.
14.Clean all gasket material from mating faces.
Refit
15.Using new gasket, fit water pump to mounting
bracket. Tighten bolts to
25 Nm (18 lbf/ft).
16.Fit power steering pump pulley.
17.Fit water pump pulley. Tighten bolts of both
pulleys to
25 Nm (18 lbf/ft).
18.Fit drive belt.See ELECTRICAL, Repair,
Auxiliary drive belt
19.Fit hose at heater rail.
20.Fit rocker cover insulation and oil filler cap.
21.Fit drive belt tensioner. Tighten retaining nut to
45 Nm (33 lbf/ft).
22.Fit intercooler top hose.
23.Fit radiator top hose.
24.Refill cooling system.
See Adjustment, Drain
and refill cooling system
25.Reconnect battery.

26COOLING SYSTEM
4
REPAIRREV: 05/99 AUXILIARY MOUNTING BRACKET AND GASKET
Service repair no - 26.50.04
Remove
1.Disconnect battery.
2.Drain cooling system
See Adjustment, Drain
and refill cooling system
.
3.Remove radiator top hose.
4.Remove intercooler top hose.
5.Remove viscous fan unit.
See Viscous
coupling and fan
6.Remove fan cowl.See Fan cowl
7.Slacken power steering pump pulley retaining
bolts.
8.Remove drive belt.
See ELECTRICAL, Repair,
Auxiliary Drive belt
9.Unscrew 3 bolts and remove power steering
pump pulley.
10.Remove 4 bolts securing power steering pump
mounting bracket.
11.Lower pump and bracket. Do not disconnect fluid
pipes.
12.Remove generator.
See ELECTRICAL, Repair,
Generator
13.Unscrew retaining nut and remove drive belt
tensioner.
14.Release hose clip from bracket above water
pump.15.Disconnect bottom hose/heater return hose at
water pump and heater rail.
16.Disconnect by-pass hose from water pump and
thermostat housing.
17.Remove 5 bolts (one with nut) and single
retaining nut, securing auxiliary mounting
bracket to cylinder block.
18.Withdraw mounting bracket, complete with water
pump.
19.Remove gasket and clean mating faces.
Refit
20.Using 2 slave studs, fit new gasket.
NOTE: All fixing bolts and nuts should be
tightened to
25 Nm (18 lbf/ft)unless
otherwise stated.
21.Locate mounting bracket, complete with water
pump on slave studs and secure with 4 other
fixings.
22.Remove slave studs and fit remaining bolts/nuts.
23.Fit by-pass hose to thermostat housing and
water pump.
24.Fit bottom hose/heater return hose to water
pump and heater rail.
25.Fit heater hose clip to mounting bracket.
26.Fit drive belt tensioner. Tighten nut to
45 Nm (33
lbf/ft).
27.Fit generator.See ELECTRICAL, Repair,
Generator
Do not fit drive belt at this stage.

COOLING SYSTEM
5
REPAIR 28.Secure steering pump and bracket to auxiliary
mounting bracket.
29.Fit steering pump pulley.
30.Fit drive belt
See ELECTRICAL, Repair,
Auxiliary drive belt
.
31.Fit fan cowl
See Fan cowl.
32.Fit viscous fan unit
See Viscous coupling and
fan
.
33.Fit intercooler top hose.
34.Fit radiator top hose.
35.Refill cooling system.
See Adjustment, Drain
and refill cooling system
36.Reconnect battery.THERMOSTAT
Service repair no - 26.45.01
Remove
1.Partially drain cooling system, until coolant level
is below thermostat housing.
2.Disconnect top hose from outlet elbow.
3.Disconnect electrical connections to water
temperature switch.
4.Unscrew 2 bolts and remove outlet elbow.
5.Withdraw thermostat. Note 88°C rating of
thermostat.
6.Place thermostat in a container half full of water.
Heat water and observe temperature at which
thermostat begins to open. Thermostat is
satisfactory if it opens between 85°-89°C.
Refit
7.Fit thermostat with jiggle pin/vent hole upwards.
8.Secure outlet elbow to thermostat housing.
Tighten bolts to
25 Nm (18 lbf/ft).
9.Fit water temperature switch connections.
10.Fit top hose to outlet elbow.
11.Refill cooling system.
See Adjustment, Drain
and refill cooling system

26COOLING SYSTEM
6
REPAIR RADIATOR
Service repair no - 26.40.01
Remove
1.Disconnect radiator bottom hose and drain
cooling system.
See Adjustment, Drain and
refill cooling system
2.Disconnect radiator top hose.
3.Remove viscous fan unit.
See Viscous
coupling and fan
4.Remove fan cowl.See Fan cowl
5.Disconnect oil cooler pipes. Plug all connections
to prevent oil spillage and ingress of dirt.
6.Disconnect top and bottom intercooler hoses.
7.Disconnect bleed hose at radiator.
8.Remove 2 bolts from both sides securing
radiator mounting brackets to bonnet platform.
9.Lift and remove radiator/intercooler assembly
from vehicle.
10.Remove 2 bolts from both sides and detach
radiator top cover from side covers.
11.Lift and remove radiator from intercooler and RH
side frame.
12.Check condition of locating grommets in radiator
top cover and lower mounting bushes. Renew if
necessary.Refit
13.Position radiator between intercooler and RH
side frame.
14.Fit radiator top cover to side covers.
15.Lower radiator/intercooler assembly into
position.
16.Secure radiator mounting brackets to bonnet
platform.
17.Fit radiator bleed hose.
18.Fit top and bottom intercooler hoses.
19.Fit oil cooler pipes.
20.Fit fan cowl
See Fan cowl.
21.Fit viscous fan unit.
See Viscous coupling
and fan
22.Fit radiator top hose.
23.Fit radiator bottom hose and refill cooling
system.
See Adjustment, Drain and refill
cooling system

COOLING SYSTEM
7
REPAIR EXPANSION TANK
Service repair no - 26.15.01
Remove
1.Position container to collect coolant spillage.
2.Slacken retaining clips and disconnect both
hoses from base of expansion tank.
3.Remove 3 bolts securing expansion tank to
inside wing and mounting bracket.
4.Remove expansion tank.
Refit
5.Fit expansion tank to inside wing and mounting
bracket.
6.Fit both hoses to base of tank.
7.Check and top up cooling system
See
SECTION 10, Maintenance, Under bonnet
maintenance