Land Rover Defender 90 Workshop 2nd Edition Nas Rover Manual

							COOLING SYSTEM
1
FAULT DIAGNOSIS ENGINE OVERHEATING
Before conducting any cooling system diagnosis:
See
Description and operation, Engine Cooling
1.Is coolant level correct?
NO - Allow engine to cool, top up level to
expansion tank seam.
YES - Continue.
2.Is coolant in radiator frozen?
YES - Slowly thaw and drain system.
See
Adjustment, Coolant Requirements
NO - Continue.
3.Is air flow through radiator restricted or blocked?
YES - Apply air pressure from engine side of
radiator to clear obstruction.
NO - Continue.
4.Are there any external leaks, from hoses,
coolant pump, engine gaskets or the heater unit?
YES - Investigate and rectify.
See Adjustment,
Coolant Requirements
NO - Continue.
5.Are fan blades fitted correct way round, concave
side towards engine?
NO - Rectify.
YES - Continue.6.Is viscous unit operating correctly?
See
Description and operation, Viscous Fan
NO - Renew.See Repair, Viscous Coupling
YES - Carry out a pressure test on radiator cap
and system. Check thermostat type,
operation and correct fitting
See Repair,
Thermostat
7.Is temperature sender and gauge giving
accurate readings?
NO - Substitute parts and compare readings.
YES - Continue.
8.Carry out cylinder pressure test to determine if
pressure is leaking into cooling system causing
over pressurising and loss of coolant.
If problem is not diagnosed, check the coolant system
for engine oil contamination and engine lubrication
system for coolant contamination.
If the coolant only, or both systems are contaminated,
suspect cylinder head gaskets or radiator.
If only the lubrication stystem is contaminated with
coolant, suspect inlet manifold or front cover gaskets. 
						

							26COOLING SYSTEM
2
FAULT DIAGNOSIS ENGINE RUNS COLD
Before conducting any cooling system diagnosis:
See
Description and operation, Engine cooling
1.Check operation of viscous unit.See
Description and operation, Viscous Fan
Is viscous unit operating correctly?
NO -
See Repair, Viscous coupling
YES - Continue.
2.Is thermostat correct type and operating?
See
Repair, Thermostat
If problem is not diagnosed: Continue.
3.Are the air conditioning fans operating
continuously?
YES -
See Electrical Trouble Shooting
Manual.
NO - Continue.
4.Is temperature sender and gauge giving
accurate readings? Substitute parts and
compare readings. If problem is not diagnosed
repeat tests, starting at 1. 
						

							COOLING SYSTEM
1
ADJUSTMENT COOLANT REQUIREMENTS
Frost precautions and engine protection.
Cooling systemMUST ALWAYSbe filled and
topped-up with solution of water and anti-freeze,
winter and summer.NEVERuse water alone, this
may corrode aluminium alloy.
CAUTION: Do not use salt water otherwise
corrosion will occur. In certain territories
where only available natural water supply
has some salt content use only rain or distilled
water.
Recommended solutions
Anti-freeze:Universal anti-freeze or permanent type
ethylene base, without methanol, containing a suitable
inhibitor for aluminium engines and engine parts.
See
LUBRICANTS, FLUIDS AND CAPACITIES,
Information, Anti-freeze
Use one part of anti-freeze to one part of water.
Anti-freeze can remain in the cooling system and will
provide adequate protection for two years provided
that specific gravity of coolant is checked before onset
of second winter and topped-up with new anti-freeze
as required.
Vehicles leaving factory have cooling system filled
with 50% solution of anti-freeze and water. This gives
protection against frost down to minus 36°C, minus
33°F. Vehicles so filled are identified by a label affixed
to radiator.
NOTE: Should ambient temperatures be
below that stated above refer to
Anti-Freeze Data in Recommended
Lubricants, Fluids and Capacities in Section 09.
Instructions in chart must be strictly adhered to
before driving vehicle.
After the second winter the system should be drained
and thoroughly flushed. Before adding new anti-freeze
examine all joints and replace defective hoses to
make sure that the system is leakproof.
For protection quantities.
See LUBRICANTS,
FLUIDS AND CAPACITIES, Information,
anti-freeze
DRAIN AND REFILL
Service repair no - 26.10.01
Drain
WARNING: Do not remove expansion tank
filler cap when engine is hot. The cooling
system is pressurised and personal
scalding could result. See coolant requirements
before refilling system.
1.Remove expansion tank filler cap by slowly
turning it anti-clockwise. Pause to allow pressure
to escape. Continue turning it in same direction
and remove.
2.Remove viscous coupling.
See Repair,
viscous coupling
3.Remove radiator filler plug and O ring to assist
drainage.
4.Position container to collect coolant spillage.
5.Loosen clip securing hose to coolant pump.
6.Release hose from coolant pump and allow
coolant to drain. 
						

							26COOLING SYSTEM
2
ADJUSTMENT
NOTE: It is not possible to drain all coolant
retained in heater system.
7.Remove engine drain plugs beneath exhaust
manifolds and allow coolant to drain from
engine.
Refill
1.Fit drain plugs to engine.
2.Connect hose to coolant pump and secure with
clip.
3.Fit viscous coupling.
See Repair, viscous
coupling
4.Pour correct solution of water and anti-freeze
into expansion tank until radiator is full.
5.Start engine and run until normal operating
temperature is reached.
6.Top up coolant level as necessary.
7.Fit new O ring to radiator filler plug.
8.Fit radiator filler plug and tighten to
6 Nm, 4 lbf
ft.
9.Fit expansion tank filler cap.
10.Allow engine to cool and check coolant level.
11.Top-up expansion tank until level reaches seam.
12.Remove container. 
						

							COOLING SYSTEM
1
REPAIR EXPANSION TANK
Service repair no - 26.15.01
Remove
WARNING: Do not remove expansion tank
filler cap when engine is hot. The cooling
system is pressurised and personal
scalding could result.
1.Remove expansion tank filler cap by slowly
turning it anti-clockwise. Pause to allow pressure
to escape then continue to turn in same direction
and remove.
2.Position container to collect any coolant spillage.
3.Loosen clip securing radiator hose to expansion
tank.
4.Release radiator hose from expansion tank.
5.Loosen clip securing coolant hose to underside
of expansion tank.
6.Release coolant hose from expansion tank.
7.Remove overflow pipe from expansion tank.
8.Remove clamping bolt from expansion tank
mounting bracket and collect nut and washer.
9.Lift mounting bracket clamp and remove
expansion tank.
Refit
10.Fit expansion tank to mounting bracket.
11.Fit and tighten nut and bolt securing expansion
tank to mounting bracket.
12.Fit overflow pipe to expansion tank.
13.Connect coolant hose to underside of expansion
tank and secure with clip.
14.Connect radiator hose to expansion tank and
secure with clip.
15.Remove container.
16.Top-up engine coolant.VISCOUS COUPLING
Service repair no - 26.25.19
Remove
1.Disconnect battery negative lead.
2.Remove 2 screws securing radiator top
mountings to fan upper cowl.
3.Release 2 clips securing fan upper cowl to lower
cowl.
4.Remove fan upper cowl. 
						

							26COOLING SYSTEM
2
REPAIR
5.Position toolLRT-12-093to hold coolant pump
pulley.
6.Loosen viscous coupling nut using tool
LRT-12-094.
7.Remove toolLRT-12-093.
8.Remove viscous coupling assembly.
Do not carry out further dismantling if component
is removed for access only.
9.Remove 4 Allen screws securing fan blades to
coupling.
10.Remove fan blades from coupling.
Refit
11.Clean mating faces of fan blades and coupling.
12.Fit fan blades to coupling and secure with Allen
screws.
13.Position coupling assembly and start tightening
nut.
14.Position toolLRT-12-093to hold pulley.
15.Tighten viscous coupling assembly nut using
toolLRT-12-094.
16.Remove tools.
17.Fit fan upper cowl and secure with clips.
18.Align fan cowl fixings to upper mounting brackets
and secure with screws.
19.Reconnect battery negative lead. 
						

							COOLING SYSTEM
3
REPAIR RADIATOR
Service repair no - 26.40.01
Remove
1.Disconnect battery negative lead.
2.Drain cooling system.
See Adjustment, drain
and refill
3.Remove 8 screws securing front grille to body.
4.Remove front grille.
5.Remove 4 bolts securing radiator top mountings
to bonnet locking panel and collect nuts.
6.Remove radiator top mountings.
7.Remove fan cowl upper mounting brackets.
8.Loosen clip and disconnect top hose from
radiator.
9.Remove 2 clips securing fasn cowl to radiator. 
						

							26COOLING SYSTEM
4
REPAIR
10.Remove fan cowl.
11.Loosen clip and disconnect throttle body to
radiator hose.
12.Loosen clip and disconnect expansion tank to
radiator hose.
13.Position container beneath engine oil cooler pipe
unions.
14.Loosen engine cooler pipes and disconnect from
radiator.
15.Remove and discard O rings from oil cooler
pipes.
16.Plug oil cooler pipe connections.
17.Loosen clip and disconnect bottom hose from
radiator.
18.Release radiator from lower mounting rubbers
and remove radiator.Refit
19.Fit radiator and secure to lower mounting
rubbers.
NOTE: Ensure condenser lower mounting
brackets are located to radiator lower
mounting brackets.
20.Connect bottom hose to radiator and secure with
clip.
21.Remove plugs from engine oil cooler pipe
connections.
22.Clean oil cooler pipe connections.
23.Lubricate NEW O rings with clean engine oil
and fit to pipes.
24.Connect oil cooler pipes to radiator and tighten
unions to
30 Nm, 22 lbf ft.
25.Remove container.
26.Connect expansion tank hose to radiator and
tighten clip.
27.Connect throttle body hose to radiator and
tighten clip.
28.Fit fan cowl to radiator.
29.Fit fan cowl lower retaining clips.
30.Connect top hose to radiator and tighten clip.
31.Fit fan upper cowl and secure with clips.
32.Fit fan cowl upper mounting brackets.
33.Fit radiator top mountings and secure with
screws and bolts.
34.Fit front grille and secure with screws.
35.Refill cooling system.
See Adjustment, drain
and refill
36.Reconnect battery negative lead. 
						

							COOLING SYSTEM
5
REPAIR THERMOSTAT
Service repair no - 26.45.01
Remove
1.Disconnect battery negative lead.
2.Drain cooling system.
See Adjustment, drain
and refill
3.Loosen clip and disconnect radiator top hose
from coolant outlet elbow.
4.Remove 2 bolts securing coolant outlet elbow to
engine.
5.Remove coolant outlet elbow and collect gasket.
6.Remove thermostat.
Refit
7.Fit thermostat ensuring jiggle pin/vent hole is
uppermost.
8.Fit coolant outlet elbow with new gasket.
9.Fit and tighten bolts securing coolant outlet
elbow to
28 Nm, 21 lbf ft.
10.Connect radiator top hose to coolant outlet
elbow tighten clip.
11.Refill cooling system.
See Adjustment, drain
and refill
12.Reconnect battery negative lead.COOLANT PUMP
Service repair no - 26.50.01
Remove
1.Drain cooling system.
See Adjustment, drain
and refill
2.Loosen coolant pump pulley bolts.
3.Release auxillary drive belt tension by turning
tensioner clockwise.
4.With tension released, remove belt from
alternator pulley.
5.Remove drive belt.
NOTE: If belt is to be refitted, mark
direction of rotation.
6.Remove bolts securing coolant pump pulley.
7.Remove coolant pump pulley. 
						

							26COOLING SYSTEM
6
REPAIR
8.Noting their fitted positions, remove 9 bolts
securing coolant pump.
9.Remove coolant pump.
10.Remove gasket.
Refit
11.Clean coolant pump and timing cover mating
faces.
12.Lightly grease NEW gasket and position to
timing cover.
13.Clean threads of all long bolts and coat with
Loctite 572 thread sealant.
14.Position coolant pump, fit bolts and tighten to
28
Nm, 21 lbf ft.
15.Fit coolant pump pulley, fit bolts but do not
tighten.
16.Clean auxillary drive belt pulley grooves and
inspect for damage.
17.Fit belt to pulleys.
18.Turn drive belt tensioner clockwise and engage
belt on alternator pulley.
19.Release drive belt tensioner.
20.Tighten coolant pump pulley bolts.
21.Refill cooling system.
See Adjustment, drain
and refill