1995 LAND ROVER DISCOVERY engine coolant

MANIFOLD AND EXHAUST SYSTEM
7
REPAIR Refit
19.Ensure mating faces of inlet manifold and
cylinder head are clean.
20.Fit a new gasket, position inlet manifold to
cylinder head.
21.Fit nuts and bolts, tighten in the order shown to
the correct torque
25Nm
22.Position engine breather hose to manifold and
secure with bolts.
23.Connect fuel injector harness and intake air
temperature sensor multiplug.
24.Connect fuel hose to pressure regulator and
secure with clip.
25.Fit fuel pipe to fuel rail, tighten union to
10Nm
26.Connect vacuum hoses to manifold.
27.Position engine harness and cam cover brackets
to manifold, secure with bolts.
28.Connect breather hose and brake servo hose to
manifold, secure with clips.
29.Connect multiplug to fuel temperature sensor.
30.Connect breather hose to throttle housing and
secure with clip.
31.Connect throttle cable to cam and secure to
abutment bracket.
32.Connect coolant bypass hose to throttle housing.
33.Connect stepper motor and throttle
potentiometer multiplugs.
34.Connect air cleaner hose to throttle housing and
secure with clip.
35.Connect battery negative lead.
36.Adjust throttle cable.EXHAUST MANIFOLD GASKET - Mpi
Service repair no - 30.15.12
Remove
1.Raise vehicle.
2.Loosen 2 nuts securing downpipe to silencer
box.
3.Remove 4 nuts securing downpipe to exhaust
manifold.
4.Release downpipe from exhaust manifold.
5.Discard gasket.

ZF
7
REPAIR Accessories removal/fitting
If fitting a replacement transmission assembly to the
vehicle, remove the following items from the existing
assembly and fit to the replacement.
CAUTION: It is important to remove the
spacer from the extension shaft and fit
onto the replacement unit.
50.Breather pipe union and washers from main
gearbox.
51.Breather pipe, union and washers from transfer
gearbox.
52.Main gearbox selector lever.
53.RH mounting bracket assembly.
54.Oil cooler pipe unions.
55.Fit blanks to all apertures where unions have
been removed and blank off pipe ends.
Refit
1.Fit transmission to cradle and hoist.
2.Locate hoist under vehicle and remove torque
convertor retaining strap.
3.Ensure low range gear is engaged.
4.Apply approved sealant to bell housing face.
5.Carefully raise assembly, align bell housing with
flywheel housing and bring mating faces
together.
6.Fit nuts and bolts to secure transmission to
engine.
7.Locate electrical wiring and breather pipes to
position.
8.Secure kick down cable clip to bell housing.
9.Raise hoist sufficiently to take weight.
10.Remove block and jack from engine sump.
11.Fit filler/dipstick tube to gearbox sump and
secure bracket to bell housing.
12.Apply Loctite to torque convertor bolts
13.Working through starter aperture refit the four
torque convertor to flexible drive securing bolts,
rotating crankshaft to gain access to bolt
locations.
14.Refit starter and heatshield.
15.Secure breather pipes and harness with ties.
16.Fit left hand mounting bracket assembly to
gearbox.
17.Raise transmission and support with a suitable
ramp [hoist] jack.
18.Remove two bolts securing transmission to
cradle, lower hoist and remove from under
vehicle.
19.Apply Loctite to above bolts and fit to transfer
gearbox input bearing support plate.
20.Fit chassis cross member.21.Secure gearbox mounting brackets to chassis
cross member.
22.Remove ramp [hoist] jack.
23.Connect electrical leads to differential lock
switch.
24.Connect inhibitor switch multi-plug.
25.Connect selector cable to lever on side of
gearbox.
26.Connect oil cooler pipes to gearbox and secure
retaining bracket to gearbox sump.
27.Secure silencer to chassis and refit exhaust front
pipe.
28.Refit front propeller shaft to transfer gearbox.
29.Refit rear propeller shaft.
See PROPELLER
SHAFTS, Overhaul, Flexible Coupling
30.Connect speedometer cable to transfer gearbox.
31.Refill transfer gearbox with correct grade of
lubricating oil.
See LUBRICANTS, FLUIDS
AND CAPACITIES, Information,
Recommended Lubricants and Fluids
32.Lower ramp [hoist] to ground level.
33.Reconnect turbo-charger hose to inter-cooler.
34.Reconnect top hose to radiator.
35.Refill cooling system with correct mixture of
coolant.
See LUBRICANTS, FLUIDS AND
CAPACITIES, Information, Recommended
Lubricants and Fluids
36.Reconnect kick down cable to fuel injection
pump.
37.Secure breather pipe clip to rear of cylinder
head.
38.Engage harness with clips along top of
bulkhead.
39.On left hand drive vehicles only, connect
multi-plug to top of brake fluid reservoir.
40.Refit insulation pad to rocker cover and inlet
manifold, secure with oil filler cap.
41.Refit gaiter and knob to transfer gear lever.
42.Select high range gear.
43.Reconnect battery terminals.
44.Refill main gearbox with correct grade of
lubricating oil.
See LUBRICANTS, FLUIDS
AND CAPACITIES, Information,
Recommended Lubricants and Fluids

HEATING AND VENTILATION
3
DESCRIPTION AND OPERATION
Controls set for unheated air to footwells and face level vents
Heater and ventilation operation
The heating and ventilation system contains a heater
matrix, which is connected to the engine cooling
system, and a 4 speed fan for air distribution. Engine
coolant is circulated through the heater matrix
continuously, except when the temperature controls
are set to COLD.
Recirculated air
When the recirculation switch is pressed, an electrical
servo operates and fully closes the fresh air intake
flap.
Fresh air
When the recirculation switch is returned to the OFF
position, the electrical servo returns and fully opens
the fresh air intake flap.Heated air
Temperature output is controlled by the temperature
controls which move the air direction and temperature
flaps independently to increase or decrease the
volume of air flow through the heater matrix.
V8 Engine:When both controls are in the cold
position, the coolant valve is turned off.
Face level vent flap
Control at face level, flap fully open. All other vents
closed.
Control at face and foot level, flaps half open.
Unless an air conditioning unit is fitted, only fresh or
re-circulated air is available from the face level vents.
Demist vent flap
Control at demist, flap fully open. All other vents
closed.
Control at demist and foot level, flaps half open.

80HEATING AND VENTILATION
4
DESCRIPTION AND OPERATION Air direction flap
Flap moves across mixing chamber to direct the air
flow away from the heater matrix.
Air temperature flap
Control at HOT, flaps fully closed. All air flow passes
through heater matrix. As control is moved towards
COLD the flaps progressively open directing air flow
away from the heater matrix.
Control at COLD, flaps fully open.
V8 Engine:When both controls are at COLD, 2
micro-switches are closed and operate a vacuum
valve which closes the coolant valve.Air conditioning
When an air conditioning unit is fitted, the mechanical
operation of the heater controls remains unaltered.
However the air conditioning evaporator is positioned
in front of the mixing chamber through which all air
flow passes.

HEATING AND VENTILATION
1
FAULT DIAGNOSIS HEATER OUTPUT
Symptom:-
Heater emits cold air.
1.Engine running: Check coolant valve opens as a
temperature control is moved from COLD.
2.Check for engine running cold.
See COOLING
SYSTEM, Fault diagnosis, Engine Runs Cold
3.Check heater pipes and hoses for blockage or
restriction.
4.Check heater matrix for blockage or restriction,
flush system.
Heater emits warm air.
5. Engine running:Check coolant valve closes
when both temperature controls are moved to
COLD.

80HEATING AND VENTILATION
4
REPAIR WATER VALVE
Service repair no - 80.10.16
Remove
1.Disconnect vacuum pipe from water valve.
2.Slacken 4 clips securing hoses to water valve.
3.Use a thin blade to break seal between hoses
and nozzles
4.Disconnect heater inlet hose from valve.
NOTE: A quantity of coolant will be
released.
5.Disconnect heater outlet hose from valve.
6.Lever valve from coolant pipe hoses.
Refit
7.Reverse removal procedure. Lightly lubricate
water valve nozzles with petroleum jelly.
8.Reverse removal procedure. Top-up engine
coolantVACUUM SWITCH - WATER VALVE
Service repair no - 80.10.36
Remove
1.Release emission pipe from retaining clip.
2.Remove bolt securing switch to bulkhead.
3.Disconnect multiplug from switch.
4.Disconnect 2 vacuum pipes and remove vacuum
switch.
Refit
5.Reverse removal procedure.

AIR CONDITIONING
3
DESCRIPTION AND OPERATION AIR CONDITIONING SYSTEM OPERATION
The air conditioning system provides the means of
supplying cooled and dehumidified, fresh or
recirculated air to the interior of the vehicle. The
cooling effect is obtained by blowing air through the
matrix of an evaporator unit and when required,
mixing that air with heated air by means of the heater
distribution and blend unit, to provide the conditions
required inside the vehicle. The volume of conditioned
air being supplied is controlled by a variable speed
blower.
A sealed system, charged with Refrigerant R134a,
together with a blower unit, blend unit and control
system combine to achieve the cooled air condition.
For air conditioning air distribution system.
See
HEATING AND VENTILATION, Description and
operation, Heating and ventilation unit
The air conditioning system comprises five major
units:
1.An engine-mounted compressor.
2.A condenser mounted in front of the radiator.
3.A receiver/drier unit located in front of the
condenser.
4.Thermostatic expansion valve mounted above
the evaporator.
5.An evaporator unit mounted in front of the heater
matrix.
NOTE: Vehicles fitted with rear air
conditioning have an additional
evaporator/blower motor assembly located
behind the LH rear compartment lower trim panel.
These units are interconnected by hoses and pipes
carrying Refrigerant R134a, the evaporator is linked
into the vehicle ventilation system.
Refrigeration cycle
1. Compressor
The compressor (1), belt driven from the crankshaft
pulley, pressurises and circulates the refrigerant
through the system. Mounted on the compressor, an
electro-mechanical clutch maintains the correct
temperature and pressure by engaging or disengaging
to support the system's requirements. The clutch
action is normally controlled by a thermostat located
at the evaporator (5). The compressor is of the
swashplate type having fixed displacement.Should the temperature at the evaporator (5) fall low
enough for ice to begin to form on the fins, the
thermostat disengages the clutch and also isolates the
cooling fans relays. When the temperature at the
evaporator (5) rises to the control temperature, the
clutch is re-engaged.
Should the system pressure become excessive or
drop sufficiently to cause damage to the compressor
(1) a dual pressure switch (7), located in the high
pressure line, signals the relay unit to disengage the
clutch. The compressor also has an emergency high
pressure relief valve (9) fitted.
The cooling fans are controlled by engine temperature
when the air conditioning is not switched on.
2. Condenser
From the compressor, hot high pressure vaporised
refrigerant (F1) passes to the condenser (2), which is
mounted in front of the engine coolant radiator. Ram
air(A1) passing through the condenser (2),
supplemented by 2 cooling fans (8) mounted in front
of the condenser, cools the refrigerant vapour
sufficiently to form a high pressure slightly subcooled
liquid (F2).
3. Receiver/drier
This liquid then passes to a receiver/drier (3) which
fulfils two functions. It acts as a reservoir and moisture
extractor (11).
A sight glass (10), in the high pressure line, provides a
method of determining the state of the refrigerant
without breaking into the system.
4. Expansion valve
From the receiver/drier (3) the moisture free high
pressure liquid refrigerant (F3) passes through a
thermostatic expansion valve (4). A severe pressure
drop occurs across the valve and as the refrigerant
enters the evaporator space at a temperature of
approximately -5°C it boils and vaporises.

82AIR CONDITIONING
4
DESCRIPTION AND OPERATION 5. Evaporator
As this change of state occurs, a large amount of
latent heat is absorbed. The evaporator is therefore
cooled and as a result heat is extracted from the air
flowing across the evaporator. The air flow is
controlled by the ventilation fan which can be
operated at anyone of four speeds.
To prevent liquid passing through to the compressor,
a capillary tube (6), attached to the outlet pipe of the
evaporator (5) and connected to the thermostatic
expansion valve (4), controls the amount that the
valve opens and closes in relation to the temperature
of the low pressure high temperature refrigerant
vapour (F4) at the outlet. The atomised refrigerant
then passes through the evaporator (5). Fan blown air
(A2) passes through the matrix (A3) of the evaporator
and is cooled by absorption due to the low
temperature refrigerant passing through the
evaporator.
A thermostat is fitted in the airflow out of the
evaporator to sense the temperature of the exterior
fins. Should ice begin to form, due to a too cold
condition, it will signal to disengage the
electro-mechanical clutch on the compressor (1).
From the evaporator, low pressure slightly
superheated refrigerant (F5) passes to the
compressor to complete the cycle.AIR CONDITIONING CONTROL SYSTEM
The air conditioning control system comprises relays,
thermostat, pressure switches, and a control panel.
Inputs from outside the air conditioning system
comprise temperature information from the engine
cooling system. Together these controls, in
conjunction with the cooling fans, compressor clutch,
blower and heater distribution and blend unit enable
minimal input to maintain the required environment
inside the vehicle.
When air conditioning is not selected, air is supplied
by ram effect or blower to the areas selected by the
controls. The air mix flap on the blend unit controls the
temperature of the air being supplied. No cooled air is
available.
Selecting air conditioning provides the added facility of
cooled air available to be mixed as before. When
required a fully cold condition can be selected by
turning the temperature controls to cold, which
automatically closes the heated coolant access to the
heater matrix. Mixtures of cooled, fresh, and hot air
can be selected to give required interior environmental
conditions by selection at the control panel.
Dual pressure switch
This switch, located in the high pressure line between
the receiver drier and the expansion valve, monitors
refrigerant pressure and by means of the relay module
controls the following system functions:
1.Refrigerant pressure drops below 2.0 bar, 29
lbf/in
2(due to possible leakage), the
compressor's electro-mechanical clutch is
dis-engaged.
When pressure rises above 2.0 bar, 29 lbf/in
2the
compressor's clutch is re-engaged.
2.Refrigerant pressure rises above 32 bar, 455
lbf/in
2(due to possible blockage), even with
cooling fan operation, the compressor's
electro-mechanical clutch is dis-engaged.
When the pressure drops below 26 bar, 375
lbf/in
2the compressor clutch is re-engaged.