heating LAND ROVER DISCOVERY 1999 Owner's Manual

COOLING SYSTEM - V8
DESCRIPTION AND OPERATION 26-2-7
Inlet manifold - Cooling connections
Coolant leaves the cylinder block via an outlet pipe attached to the front of the air intake manifold. The pipe is
connected to the thermostat housing and the radiator by a branch hose off the radiator top hose.
Hot coolant from the engine is also directed from the inlet manifold via pipes and hoses into the heater matrix. Coolant
is circulated through the heater matrix at all times when the engine is running.
A further tapping from the inlet manifold supplies coolant to the throttle housing via a hose. The coolant circulates
through a plate attached to the bottom of the housing and is returned through a plastic bleed pipe to an expansion
tank. The hot coolant heats the air intake of the throttle housing preventing ice from forming.
An Engine Coolant Temperature (ECT) sensor is fitted in the inlet manifold adjacent to the manifold outlet pipe. The
sensor monitors coolant temperature emerging from the engine and sends signals to the ECM for engine
management and temperature gauge operation.

+ ENGINE MANAGEMENT SYSTEM - V8, DESCRIPTION AND OPERATION, Description - engine
management.
Expansion tank
The expansion tank is located in the engine compartment. The tank is made from moulded plastic and attached to
brackets on the right hand inner wing. A maximum coolant when cold level is moulded onto the tank.
Excess coolant created by heat expansion is returned to the expansion tank from the radiator bleed pipe at the top of
the radiator. An outlet pipe is connected into the pump feed hose and replaces the coolant displaced by heat
expansion into the system when the engine is cool.
The expansion tank is fitted with a sealed pressure cap. The cap contains a pressure relief valve which opens to allow
excessive pressure and coolant to vent through the overflow pipe. The relief valve opens at a pressure of 1.4 bar (20
lbf.in
2) and above.
Heater matrix
The heater matrix is fitted in the heater assembly inside the passenger compartment. Two pipes pass through the
bulkhead into the engine compartment and provide coolant flow to and from the matrix. The pipes from the bulkhead
are connected to the matrix, sealed with 'O' rings and clamped with circular rings.
The matrix is constructed from aluminium with two end tanks interconnected with tubes. Aluminium fins are located
between the tubes and conduct heat away from the hot coolant flowing through the tubes. Air from the heater
assembly is warmed as it passes through the matrix fins. The warm air is then distributed into the passenger
compartment as required.

+ HEATING AND VENTILATION, DESCRIPTION AND OPERATION, Description.When the engine is
running, coolant from the engine is constantly circulated through the heater matrix.
Radiator
The 45 row radiator is located at the front of the vehicle. The cross-flow type radiator is manufactured from aluminium
with moulded plastic end tanks interconnected with tubes. Aluminium fins are located between the tubes and conduct
heat from the hot coolant flowing through the tubes, reducing the cooling temperature as it flows through the radiator.
Air intake from the front of the vehicle when moving carries heat away from the fins. When the vehicle is stationary,
the viscous fan draws air through the radiator fins to prevent the engine from overheating.
Two connections at the top of the radiator provide for the attachment of the top hose and bleed pipe. A connection at
the bottom of the radiator allows for the attachment of the bottom hose to the thermostat housing.
Two smaller radiators are located in front of the cooling radiator. The lower radiator provides cooling of the gearbox
oil and the upper radiator provides cooling for the engine oil.

+ MANUAL GEARBOX - R380, DESCRIPTION AND OPERATION, Description.

+ AUTOMATIC GEARBOX - ZF4HP22 - 24, DESCRIPTION AND OPERATION, Description.

+ ENGINE - V8, DESCRIPTION AND OPERATION, Description.
Pipes and hoses
The coolant circuit comprises flexible hoses and metal formed pipes which direct coolant into and out of the engine,
radiator and heater matrix. Plastic pipes are used for the bleed and overflow pipes to the expansion tank.
A bleed screw is installed in the radiator top hose and is used to bleed air during system filling. A drain plug is fitted
to each cylinder bank in the cylinder block. These are used to drain the block of coolant.

CLUTCH - V8
33-2-6 DESCRIPTION AND OPERATION
Description
General
The clutch system is a conventional diaphragm type clutch operated by a hydraulic cylinder. The clutch requires no
adjustment to compensate for wear.
Hydraulic clutch
The hydraulic clutch comprises a master cylinder, slave cylinder and a hydraulic reservoir, which is also shared with
the braking system. The master and slave cylinders are connected to each other hydraulically by plastic and metal
pipes. The plastic section of the pipe allows ease of pipe routing and also absorbs engine movements and vibrations.
The master cylinder comprises a body with a central bore. Two ports in the body connect the bore to the hydraulic
feed pipe to the slave cylinder and the brake/clutch fluid reservoir. A piston is fitted in the bore and has an external
rod which is attached to the clutch pedal with a pin. Two coiled springs on the clutch pedal reduce the effort required
to depress the pedal.
The master cylinder is mounted on the bulkhead in the engine compartment and secured with two bolts. The cylinder
is connected to the shared brake/clutch reservoir on the brake servo by a braided connecting hose.
The slave cylinder is located on the left hand side of the gearbox housing and secured with two bolts. A heat shield
protects the underside of the cylinder from heat generated from the exhaust system. The slave cylinder comprises a
cylinder with a piston and a rod. A port in the cylinder body provides the attachment for the hydraulic feed pipe from
the master cylinder. A second port is fitted with a bleed nipple for removing air from the hydraulic system after
servicing. The piston rod locates on a clutch release lever located in the gearbox housing. The rod is positively
retained on the release lever with a clip.
Clutch mechanism
The clutch mechanism comprises a flywheel, drive plate, pressure plate, release lever and a release bearing. The
clutch mechanism is fully enclosed at the rear of the engine by the gearbox housing.
A clutch release bearing sleeve is attached in the gearbox housing with two bolts and located on two dowels. A spigot
with a ball end is formed on the release bearing sleeve and provides a mounting and pivot point for the clutch release
lever. A dished pivot washer is located on the ball of the spigot. When the release lever is located on the ball, the pivot
washer seats against the rear face of the release lever. A spring clip is located on the lever and the pivot washer and
secures the lever on the spigot. A small bolt retains the spring clip in position.
The release lever is forked at its inner end and locates on the clutch release bearing carrier. The outer end of the
release lever has a nylon seat which locates the slave cylinder piston rod. A second nylon seat, positioned centrally
on the release lever, locates on the ball spigot of the release bearing sleeve and allows the release lever to pivot freely
around the ball.
The clutch release bearing locates on the clutch release lever and the release bearing sleeve. The bearing is retained
on a carrier which has two flats to prevent the carrier rotating on the release lever. A clip retains the release lever on
the carrier. The bearing and carrier are not serviceable individually.
Flywheel
The flywheel is bolted to a flange on the rear of the crankshaft with six bolts. A dowel on the crankshaft flange ensures
that the flywheel is correctly located. A ring gear is fitted on the outside diameter of the flywheel and seats against a
flange. The ring gear is an interference fit on the flywheel and is installed by heating the ring and cooling the flywheel.
The ring gear is a serviceable item and can be replaced if damaged or worn.
The operating face of the flywheel is machined to provide a smooth surface for the drive plate to engage on. Three
dowels and six threaded holes provide for the location and attachment of the pressure plate. The flywheel is balanced
to ensure that it does not produce vibration when rotating. A machined slot, with a series of holes within the slot, is
located on the engine side of the flywheel. The slot accommodates the tip of the crankshaft position sensor which is
used by the Engine Control Module (ECM) for engine management.

+ ENGINE MANAGEMENT SYSTEM - V8, DESCRIPTION AND OPERATION, Description - engine
management.

BRAKES
70-22 DESCRIPTION AND OPERATION
Minimum target speed
The minimum target speed depends on which gear is engaged. Reduced minimum target speeds are employed for
some gears if rough terrain or sharp bends are encountered while already travelling at the normal minimum target
speed. If loss of traction makes it impossible to maintain the minimum target speed, the SLABS ECU temporarily
increases the minimum target speed to maintain stability, then restores the normal minimum target speed when
traction improves.
HDC minimum target speeds
Fade out
To provide a safe transition from active braking to brakes off, the SLABS ECU invokes a fade out strategy if it detects
any of the following during active braking:
lA system fault.
lThe conditions for HDC are no longer being met.
lPossible brake overheat.
The fade out strategy increases the target speed at a low constant acceleration rate, independent of actual throttle
position. This results in the braking effort being gradually reduced and then discontinued. The SLABS ECU operates
warning indications during fade out that are dependent on the cause.
Fade out warning indications
Clutch disengagement/neutral selection
During active braking, if the SLABS ECU detects the clutch is disengaged or neutral is selected, it flashes the HDC
information warning lamp and sounds the audible warning continuously to indicate that conditions for HDC are no
longer being met. Initially, the SLABS ECU also fixes the target speed to the applicable minimum target speed, but if
the condition continues for approximately 60 seconds the SLABS ECU invokes fade out.
Brake overheat prevention
To prevent the brakes overheating, the SLABS ECU monitors the amount of active braking employed and, from this,
estimates brake temperature. If the SLABS ECU estimates the brake temperature has exceeded a preset limit, it
flashes the HDC fault warning lamp and sounds the audible warning continuously, to indicate that HDC should be
deselected to allow the brakes to cool. If active braking continues and the SLABS ECU estimates that brake
temperature has increased to an unacceptable level, fade out is employed and HDC is disabled. After fade out, the
audible warning is discontinued but the HDC fault warning lamp continues to flash, while HDC is selected, until the
SLABS ECU estimates brake temperature to be at an acceptable level. This calculation continues even if the ignition
is turned off, so turning the ignition off and back on will not reduce the disabled time. When the SLABS ECU estimates
the brake temperature to be acceptable, it extinguishes the HDC fault warning lamp and illuminates the HDC
information warning lamp to indicate that HDC is re-enabled. The disabled time is dependent on vehicle speed; typical
times at constant vehicle speeds are as follows:
Gear Speed, mph (km/h)
Manual gearbox Automatic gearbox
Normal Reduced Normal Reduced
1 4.4 (7.0) 4.4 (7.0) 4.4 (7.0) 4.4 (7.0)
2 5.2 (8.3) 4.4 (7.0) 4.4 (7.0) 4.4 (7.0)
3 6.0 (9.6) 4.4 (7.0) 7.5 (12.0) 6.0 (9.6)
4 7.5 (12.0) 6.0 (9.6) 7.5 (12.0) 6.0 (9.6)
5 8.8 (14.0) 7.0 (11.2) - -
Reverse 3.5 (5.6) 3.5 (5.6) 3.5 (5.6) 3.5 (5.6)
Neutral or clutch
disengaged8.8 (14.0) Last off road speed 4.4 (7.0) 4.4 (7.0)
Cause Warning indication
HDC fault warning lamp HDC information
warning lampAudible warning
Fault detected On Flashes Continuous
HDC conditions not met Off Flashes Continuous
Brake overheat prevention Flashes Off Continuous

SCREENS
76-4-2 REPAIRS
Windscreen
$% 76.81.01
Introduction
The following equipment is required:
lCutting wire and handles.
lKent cutting knife.
lGlazing knife.
lWindscreen repair kit.
lSealant applicator gun.
lSuction cups.
lA felt covered table or stand to support glass.
WARNING: Wear protective gloves when
handling glass, solvents and primers.
WARNING: Wear suitable eye protection when
removing and refitting glass.
WARNING: If glass has splintered, protect eyes
and operate demister blower to remove glass
from heater ducts. Use a vacuum cleaner to
remove glass from fascia, carpet and seats.Remove
1.Remove air intake plenum.

+ HEATING AND VENTILATION,
REPAIRS, Plenum Air Intake.
2.If fitted, disconnect screen heater multiplugs.
3.Remove top corner trim finishers from body.
4.Remove windscreen top finisher and discard.
5.Release interior mirror from slug and tie aside.
6.Fit protection to exterior body work adjacent to
screen.
7.Cover body panels adjacent to glass.
8.Cover heater ducts with masking tape.
9.Cover interior of vehicle with protective sheet.

SCREENS
76-4-4 REPAIRS
15.Apply a continuous bead of sealant to sealant
face on screen as shown.
16.With assistance, lift screen into place and align
to screen supports and tape. Ensure top
finisher is located into correct position. Lightly
press glass to fully seat sealer.
CAUTION: Do not apply heavy pressure to
the sides of the windscreen. Lightly press
windscreen from centre outwards until
edges are to required gap. Pushing sides
into position can bend windscreen and lead
to cracking in service.
17.Remove protective covers and tape.
18.Test sealer for leaks, apply additional sealer if
necessary. If water is used, allow sealer to dry
before testing. Spray water around glass and
check for leaks. Mark any area that leaks. Dry
glass and sealer then apply additional sealer.
19.Fit interior mirror to slug.
20.If applicable, connect screen heater multiplugs.
21.Fit air intake plenum.

+ HEATING AND VENTILATION,
REPAIRS, Plenum Air Intake.
CAUTION: A curing time of 6 hours is
desirable. During this time leave a window
open to ventilate the vehicle interior. If the
vehicle must be used before the curing time
has elapsed, do not drive at speed or slam
the doors with the windows closed.
CAUTION: Vehicles fitted with a passenger
airbag should not be driven for 24 hours.
Glass - body side - rear
$% 76.81.18
Introduction
The following equipment is required:
lCutting wire and handles.
lKent cutting knife.
lGlazing knife.
lWindscreen repair kit.
lSealant applicator gun.
lSuction cups.
lA felt covered table or stand to support glass.
WARNING: Wear protective gloves when
handling glass, solvents and primers.
WARNING: Wear suitable eye protection when
removing and refitting glass.
Remove
1.If fitted, disconnect coaxial cable from terminal
on glass.
2.Fit protection to exterior body work adjacent to
glass.
3.Cover body panels adjacent to glass.
4.Fit protection to internal trim adjacent to glass.
5.Cover interior of vehicle with protective sheet.

SEATS
REPAIRS 76-5-21
Refit
1.Fit cover to cushion.
2.Fit and clamp hog rings securing cover to
cushion.
3.Fit outer edges of cover over cushion.
4.Fit cushion and cover assembly to seat frame.
5. Models with seat heaters: Connect seat
heater multiplug.
6.Secure rear edge of cushion cover with clip.
7.Fit end clips over rear edge of cushion cover.
8.Secure lower edge of squab cover to seat
frame.
9.Secure edges of cushion cover with clips.
10.Secure front edge of cushion cover with clip.
11.Position seat correct way up on work bench.
12.Secure inner edge trim casing to seat frame.
13.Fit outer edge trim casing to seat frame and
secure with screws.
14.Fit front seat.

+ SEATS, REPAIRS, Seat - front.
Heating element - cushion - front seat
$% 78.30.24
Remove
1.Remove front seat cushion cover.

+ SEATS, REPAIRS, Cover - cushion
- front seat.
2.Carefully release heating element from
cushion pad, ensuring adhesive does not tear
cushion pad.
Refit
1.Ensure cushion pad is free of adhesive.
2.Remove adhesive cover from new heating
element, position element and secure to
cushion pad.
3.Fit front seat cushion cover.

+ SEATS, REPAIRS, Cover - cushion
- front seat.

SEATS
REPAIRS 76-5-33
Heating element - squab - front seat
$% 78.90.36
Remove
1.Remove front seat squab cover.

+ SEATS, REPAIRS, Cover - squab -
front seat.
2.Disconnect heating element multiplug.
3.Carefully release heating element from squab
pad, ensuring adhesive does not tear squab
pad.
Refit
1.Ensure squab pad is free of adhesive.
2.Remove adhesive cover from new heating
element, position element and secure to squab
pad.
3.Fit front seat squab cover.

+ SEATS, REPAIRS, Cover - squab -
front seat.
Head restraint - third row seat
$% 78.50.10
Remove
1.Fold down both third row head restaints.
2.Release upper tail gate finisher from 6 clips and
remove finisher.
3.Remove 3 bolts securing head restraint and
remove head restraint.
Refit
1.Position head restraint, fit and tighten bolts.
2.Position upper tail gate finisher and secure in
clips.
M78 0493
M78 0494

HEATING AND VENTILATION
DESCRIPTION AND OPERATION 80-1
HEATING A ND VENT ILATION DESCRIPTION AND OPERAT ION
Heating and ventilation component
layout
RH drive shown, LH drive similar
1Control panel
2Outlet vent
3Rear footwell ducts4Front footwell duct
5Air inlet duct
6Heater assembly

HEATING AND VENTILATION
80-2DESCRIPTION AND OPERATION
Fuel burning heater component layout
RH drive shown, LH drive similar
1FBH fuel line connection
2FBH unit3Air temperature sensor
4FBH pump

HEATING AND VENTILATION
DESCRIPTION AND OPERATION 80-3
Description
General
The heating and ventilation system controls the temperature and distribution of air supplied to the vehicle interior. The
system consists of an air inlet duct, heater assembly, distribution ducts and a control panel. An outlet vent is
incorporated at the rear of the cabin. Some diesel models also incorporate a fuel burning heater (FBH) system in the
engine coolant supply to the heater assembly.
Fresh or recirculated air flows into the heater assembly from the inlet duct. An electrical variable speed blower in the
inlet duct, and/or ram effect, forces the air through the system. Depending on the settings on the control panel, the air
is then heated and supplied through the distribution ducts to fascia and floor level outlets.