1999 LAND ROVER DISCOVERY ABS

CONTENTS
CONTENTS 17
BRAKES ................................................................................................... 70-1
DESCRIPTION AND OPERATION
Brake system control component layout ......................................................................................... 70-1
Brake system control diagram ........................................................................................................ 70-2
Brake system hydraulic component layout ..................................................................................... 70-4
Description ...................................................................................................................................... 70-5
Operation ........................................................................................................................................ 70-20
DESCRIPTION AND OPERATION
Handbrake component layout ......................................................................................................... 70-25
Description ...................................................................................................................................... 70-26
ADJUSTMENTS
Handbrake .................................................................................................................................... 70-29
Brake system bleeding ................................................................................................................... 70-30
REPAIRS
Brake disc - front .......................................................................................................................... 70-33
Brake disc - rear ............................................................................................................................ 70-34
Master cylinder - brake ................................................................................................................. 70-35
Cable - handbrake ........................................................................................................................ 70-36
Switch - brake light ........................................................................................................................ 70-37
Brake pads - front ......................................................................................................................... 70-38
Brake pads - rear .......................................................................................................................... 70-39
Brake shoes - handbrake ................................................................................................................ 70-40
Servo - brake .................................................................................................................................. 70-42
Vacuum pump - servo ..................................................................................................................... 70-43
Housing - caliper - front ................................................................................................................. 70-45
Housing - caliper - rear ................................................................................................................. 70-46
ECU - Self levelling and anti locking brakes (SLABS) ................................................................. 70-47
Sensor – ABS – front ..................................................................................................................... 70-48
Sensor – ABS – rear ....................................................................................................................... 70-48
Modulator unit - ABS ...................................................................................................................... 70-49
Switch - Hill descent control ............................................................................................................ 70-50
Switch - handbrake ....................................................................................................................... 70-50

INTRODUCTION
01-3
Abbreviations and Symbols
A Amperes
AAP Ambient Air Pressure
ABDC After Bottom Dead Centre
ABS Anti-Lock Brake System
ac Alternating current
A/C Air Conditioning
ACE Active Cornering Enhancement
ACEA Association of Constructors of
European Automobiles
AFR Air Fuel Ratio
AP Ambient Pressure
ASC Anti-shunt Control
ATC Air Temperature Control
ATDC After Top Dead Centre
BBDC Before Bottom Dead Centre
BBUS Battery Backed Up Sounder
BCU Body Control Unit
BDC Bottom Dead Centre
bhp Brake Horse Power
BP Boost Pressure
BPP Brake Pedal Position
BS British Standard
BTDC Before Top Dead Centre
C Celsius
CAN Controller Area Network
CD Compact Disc
CDC Centre Differential Control
CDL Central Door Locking
CD - ROM Compact Disc - Read Only
Memory
CFC Chlorofluorocarbon
CHMSL Centre High Mounted Stop Lamp
CKP Crankshaft Position
CLV Calculated Load Value
cm Centimetre
cm
2Square centimetre
cm3Cubic centimetre
CMP Camshaft Position
CPP Clutch Pedal Position
CO Carbon Monoxide
CO
2Carbon Dioxide
CR Common Rail
CVS Canister Vent Solenoid
deg. Degree, angle or temperature
dia. Diameter
DIN Deutsche Industrie Normen
(German Industrial Standards)
dc Direct current
DCV Directional Control Valve
DOHC Double Overhead Camshaft
DTI Dial Test Indicator
DFM Dual Mass Flywheel
DVD Digital Versatile Disc
EACV Electronic Air Control Valve EAT Electronic Automatic
Transmission
EBD Electronic Brake pressure
Distribution
ECD European Community Directive
ECM Engine Control Module
ECT Engine Coolant Temperature
ECU Electronic Control Unit
EDC Electronic Diesel Control
EEPROM Electronic Erasable
Programmable Read Only
Memory
EGR Exhaust Gas Recirculation
EKA Emergency Key Access
EN European Norm
EOBD European On Board Diagnostics
ETC Electronic Traction Control
EUI Electronic Unit Injector
EVAP Evaporative Emission
EVR Electronic Vacuum Regulator
F Fahrenheit
FBH Fuel Burning Heater
FIP Fuel Injection Pump
FTC Fast Throttle Control
g Gramme or Gravity
hHour
hc High compression
HC Hydro Carbons
HDC Hill Descent Control
HDPE High Density Polyethylene
HFS Heated Front Screen
Hg Mercury
HO2S Heated Oxygen Sensor
HMW High Molecular Weight
HRW Heated Rear Window
ht/HT High tension
IACV Idle Air Control Valve
IAT Intake Air Temperature
ICE In-Car Entertainment
i.dia. Internal diameter
IDM Intelligent Driver Module
in3Cubic inch
ILT Inlet Throttle
ISO International Organisation for
Standardisation
k Thousand
kg Kilogramme
km Kilometre
km/h Kilometres per hour
kPa KiloPascal
KS Knock Sensor
lLitre
lbf.in Pounds force inches
lbf/in
2Pounds per square inch
lbf.ft Pounds force feet

INTRODUCTION
01-4
λLambda
lc Low compression
LCD Liquid Crystal Display
LED Light Emitting Diode
LH Left-Hand
LHD Left-Hand Drive
LVS Liquid Vapour Separator
mMetre
µMicro
MAF Mass Air Flow
MAP Manifold Absolute Pressure
MFU Multi-Function Unit
MFL Multi-Function Logic
max. Maximum
MEMS Modular Engine Management
System
MIL Malfunction Indicator Lamp
min. Minimum
MPa MegaPascal
- Minus (tolerance)
' Minute (angle)
mm Millimetre
mph Miles per hour
MPi Multi-Point injection
MY Model Year
NAS North American Specification
(-) Negative (electrical)
Nm Newton metre
No. Number
NO
2Nitrogen Dioxide
NO
xOxides of Nitrogen
NTC Negative Temperature
Coefficient
OBD On Board Diagnostics
o.dia. Outside diameter
ORM Off-road Mode
ΩOhm
PAS Power Assisted Steering
PCV Positive Crankcase Ventilation
PDC Parking Distance Control
% Percentage
+ Plus (tolerance) or Positive
(electrical)
±Plus or minus (tolerance)
PTC Positive Temperature Coefficient
PTFE Polytetrafluorethylene
PWM Pulse Width Modulation
rRadius
:Ratio
ref Reference
RES Rover Engineering Standards
rev/min Revolutions per minute
RF Radio Frequency
RH Right-Hand
RHD Right-Hand Drive
ROM Read Only Memory
RON Research Octane Number
ROV Roll Over ValveROW Rest Of World
SAE Society of Automotive Engineers
" Second (angle)
SLABS Self Levelling and Anti-Lock
Brake System
SLS Self Levelling Suspension
SOHC Single Overhead Camshaft
sp.gr Specific gravity
SRS Supplementary Restraint System
std. Standard
synchro Synchronizer or synchromesh
TDC Top Dead Centre
TMAP Temperature, Manifold Absolute
Pressure
TP Throttle Position
TPS Throttle Position Sensor
TV Torsional Vibration
TXV Thermostatic Expansion Valve
UK United Kingdom
US United States
V Volt
Var. Variable
VIN Vehicle Identification Number
VIS Variable Intake System
VRS Variable Reluctance Sensor
VSS Vehicle Speed Signal
WWatt

GENERAL INFORMATION
03-2
Safety Instructions
Whenever possible, use a lift or pit when working
beneath vehicle, in preference to jacking. Chock
wheels as well as applying parking brake.
Jacking
Always use the recommended jacking points.
Always ensure that any lifting apparatus has
sufficient load capacity for the weight to be lifted.
Ensure the vehicle is standing on level ground prior
to lifting or jacking.
Apply the handbrake and chock the wheels.
WARNING: Do not work on or under a vehicle
supported only by a jack. Always support the
vehicle on safety stands.
Do not leave tools, lifting equipment, spilt oil, etc.
around or on the work bench area. Always keep a
clean and tidy work area.
Brake shoes and pads
Always fit the correct grade and specification of
brake linings. When renewing brake pads and brake
shoes, always replace as complete axle sets.Brake hydraulics
Observe the following recommendations when
working on the brake system:
lAlways use two spanners when loosening or
tightening brake pipe or hose connections.
lEnsure that hoses run in a natural curve and are
not kinked or twisted.
lFit brake pipes securely in their retaining clips
and ensure that the pipe cannot contact a
potential chafing point.
lContainers used for brake fluid must be kept
absolutely clean.
lDo not store brake fluid in an unsealed
container, it will absorb water and in this
condition would be dangerous to use due to a
lowering of its boiling point.
lDo not allow brake fluid to be contaminated with
mineral oil, or put new brake fluid in a container
which has previously contained mineral oil.
lDo not re-use brake fluid removed from the
system.
lAlways use clean brake fluid or a recommended
alternative to clean hydraulic components.
lAfter disconnection of brake pipes and hoses,
immediately fit suitable blanking caps or plugs to
prevent the ingress of dirt.
lOnly use the correct brake fittings with
compatible threads.
lObserve absolute cleanliness when working
with hydraulic components.
Cooling system caps and plugs
Extreme care is necessary when removing
expansion tank caps and coolant drain or bleed
screws when the engine is hot, especially if it is
overheated. To avoid the possibility of scalding,
allow the engine to cool before attempting removal.
Air suspension system
Whilst working on the air suspension system, eye
protection must be worn at all times.

GENERAL INFORMATION
03-4
Spill kits
Special materials are available to absorb a number of
different substances. They can be in granular form,
ready to use and bought in convenient containers for
storage. Disposal of used spill-absorbing material is
dealt with in 'Waste Management' section.
Land contamination
Oils, fuels and solvents etc. can contaminate any soil
that they are allowed to contact. Such materials
should never be disposed of by pouring onto soil and
every precaution must be taken to prevent spillage
reaching soil. Waste materials stored on open
ground could also leak, or have polluting substances
washed off them that would contaminate the land.
Always store these materials in suitable skips or
other similarly robust containers.
Checklist
Always adhere to the following.
lDon't pour or spill anything onto the soil or bare
ground;
ldon't store waste materials on bare ground, see
'Spillage prevention' list.
Legal compliance
Some sites may have a discharge consent for
effluent discharge to the foul drain for a car wash etc.
It is important to know what materials are allowed in
the drain and to check the results of any monitoring
carried out by the Water Company.
Where paint-spraying operations are carried out it
may be necessary to apply to the Local Authority for
an air emissions licence to operate the plant. If such
a licence is in operation, additional precautions will
be necessary to comply with the requirements, and
the results of any air quality monitoring must be
checked regularly.
Checklist
Always adhere to the following.
lKnow what legal consents and licences apply to
the operations;
lcheck that the emissions and discharges
comply with legal requirements.
Local issues
A number of environmental issues will be of
particular concern to residents and other neighbours
close to the site. The sensitivity of these issues will
depend on the proximity of the site and the layout
and amount of activity carried on at the site.
Noise is a major concern and therefore
consideration should be given to the time spent
carrying out noisy activities and the location of those
activities that can cause excessive noise. Car alarm testing, panel beating, hammering and
other such noisy activities should, whenever
possible, be carried out indoors with doors and
windows shut or as far away from houses as
possible.
Running vehicle engines may be an outside activity
which could cause nuisance to neighbours because
of both noise and smell.
Be sensitive to the time of day when these activities
are carried out and minimise the time of the noisy
operation, particularly in the early morning and late
evening.
Another local concern will be the smell from the
various materials used. Using less solvent, paint
and petrol could help prevent this annoyance.
Local residents and other business users will also be
concerned about traffic congestion, noise and
exhaust fumes, be sensitive to these concerns and
try to minimise inconvenience from deliveries,
customers and servicing operations.
Checklist
Always adhere to the following.
lIdentify where the neighbours who are likely to
be affected are situated;
lminimise noise, smells and traffic nuisance;
lprevent litter by putting waste in the correct
containers;
lhave waste skips emptied regularly.
Use of resource
Another environmental concern is the waste of
materials and energy that can occur in day to day
activities.
Electricity for heating, lighting and compressed air
uses resources and releases pollution during its
generation.
Fuel used for heating, running cars or vans and
mobile plant is another limited resource which
consumes large amounts of energy during its
extraction and refining processes.
Water has to be cleaned, piped to site and disposed
of; all of which creates more potential pollution.
Oil, spares, paint etc., have all produced pollution in
the process of manufacture and they become a
waste disposal problem if discarded.

GENERAL INFORMATION
03-5
Checklist
Always adhere to the following.
Electricity and heating:
lkeep doors and windows closed in the winter;
lswitch off machinery or lights when not needed;
luse energy efficient heating systems;
lswitch off computers and photocopiers when
not needed.
Fuel:
ldon't run engines unnecessarily;
lthink about whether journeys are necessary and
drive to conserve fuel.
Water:
ldon't leave taps and hose pipes running;
lmend leaks quickly, don't be wasteful.
Compressed air:
ldon't leave valves open;
lmend leaks quickly;
ldon't leave the compressor running when not
needed.
Use of environmentally damaging materials:
lcheck whether a less toxic material is available.
Handling and storage of materials:
lhave the correct facilities available for handling
liquids to prevent spillage and wastage as listed
above;
lprovide suitable locations for storage to prevent
frost damage or other deterioration.
Waste Management
One of the major ways that pollution can be reduced
is by the careful handling, storage and disposal of all
waste materials that occur on sites. Legislation
makes it illegal to dispose of waste materials other
than to licensed waste carriers and disposal sites.
This means that it is necessary to not only know what
the waste materials are, but also to have the
necessary documentation and licenses.
Handling and storage of waste
Ensure that waste materials are not poured down the
drain or onto soils. They should be stored in such a
way as to prevent the escape of the material to land,
water or air.
They must also be segregated into different types of
waste e.g. oil, metals, batteries, used vehicle
components. This will prevent any reaction between
different materials and assist in disposal.Disposal of waste
Disposal of waste materials must only be to waste
carriers who are licensed to carry those particular
waste materials and all the necessary
documentation must be completed. The waste
carrier is responsible for ensuring that the waste is
taken to the correct disposal sites.
Dispose of waste in accordance with the following
guidelines.
lFuel, hydraulic fluid, anti-freeze and oil: keep
separate and dispose of to specialist contractor.
lRefrigerant: collect in specialist equipment and
reuse.
lDetergents: safe to pour down the foul drain if
diluted.
lPaint, thinners: keep separate and dispose of
to specialist contractor.
lComponents: send back to supplier for
refurbishment, or disassemble and reuse any
suitable parts. Dispose of the remainder in
ordinary waste.
lSmall parts: reuse any suitable parts, dispose
of the remainder in ordinary waste.
lMetals: can be sold if kept separate from
general waste.
lTyres: keep separate and dispose of to
specialist contractor.
lPackaging: compact as much as possible and
dispose of in ordinary waste.
lAsbestos-containing: keep separate and
dispose of to specialist contractor.
lOily and fuel wastes (e.g. rags, used spill kit
material): keep separate and dispose of to
specialist contractor.
lAir filters: keep separate and dispose of to
specialist contractor.
lRubber/plastics: dispose of in ordinary waste.
lHoses: dispose of in ordinary waste.
lBatteries: keep separate and dispose of to
specialist contractor.
lAirbags - explosives: keep separate and
dispose of to specialist contractor.
lElectrical components: send back to supplier
for refurbishment, or disassemble and reuse
any suitable parts. Dispose of the remainder in
ordinary waste.
lElectronic components: send back to supplier
for refurbishment, or disassemble and reuse
any suitable parts. Dispose of the remainder in
ordinary waste.
lCatalysts: can be sold if kept separate from
general waste
lUsed spill-absorbing material: keep separate
and dispose of to specialist contractor.
lOffice waste: recycle paper and toner and ink
cartridges, dispose of the remainder in ordinary
waste.

GENERAL INFORMATION
03-6
General Fitting Instructions
Component removal
Whenever possible, clean components and
surrounding area before removal.
lBlank off openings exposed by component
removal.
lImmediately seal fuel, oil or hydraulic lines when
apertures are exposed; use plastic caps or
plugs to prevent loss of fluid and ingress of dirt.
lClose the open ends of oilways exposed by
component removal with tapered hardwood
plugs or conspicuous plastic plugs.
lImmediately a component is removed, place it in
a suitable container; use a separate container
for each component and its associated parts.
lClean bench and provide marking materials,
labels and containers before dismantling a
component.
Dismantling
Observe scrupulous cleanliness when dismantling
components, particularly when brake, fuel or
hydraulic system parts are being worked on. A
particle of dirt or a cloth fragment could cause a
serious malfunction if trapped in these systems.
lBlow out all tapped holes, crevices, oilways and
fluid passages with an air line. Ensure that any
'O' rings used for sealing are correctly replaced
or renewed, if disturbed during the process.
lUse marking ink to identify mating parts and
ensure correct reassembly. Do not use a centre
punch or scriber to mark parts, they could
initiate cracks or distortion in marked
components.
lWire together mating parts where necessary to
prevent accidental interchange (e.g. roller
bearing components).
lWire labels on to all parts which are to be
renewed, and to parts requiring further
inspection before being passed for reassembly;
place these parts in separate containers from
those containing parts for rebuild.
lDo not discard a part due for renewal until after
comparing it with a new part, to ensure that its
correct replacement has been obtained.Cleaning components
Always use the recommended cleaning agent or
equivalent. Ensure that adequate ventilation is
provided when volatile degreasing agents are being
used. Do not use degreasing equipment for
components containing items which could be
damaged by the use of this process.
General inspection
All components should be inspected for wear or
damage before being reassembled.
lNever inspect a component for wear or
dimensional check unless it is absolutely clean;
a slight smear of grease can conceal an
incipient failure.
lWhen a component is to be checked
dimensionally against recommended values,
use the appropriate measuring equipment
(surface plates, micrometers, dial gauges etc.).
Ensure the measuring equipment is calibrated
and in good serviceable condition.
lReject a component if its dimensions are
outside the specified tolerances, or if it appears
to be damaged.
lA part may be refitted if its critical dimension is
exactly to its tolerance limit and it appears to be
in satisfactory condition. Use 'Plastigauge' 12
Type PG-1 for checking bearing surface
clearances.

GENERAL INFORMATION
03-7
Ball and Roller Bearings
General
When removing and installing bearings, ensure that
the following practices are observed to ensure
component serviceability.
lRemove all traces of lubricant from bearing
under inspection by cleaning with a suitable
degreasant; maintain absolute cleanliness
throughout operations.
lConduct a visual inspection for markings on
rolling elements, raceways, outer surface of
outer rings or inner surface of inner rings. Reject
any bearings found to be marked, since marking
in these areas indicates onset of wear.
lHold inner race of bearing between finger and
thumb of one hand and spin outer race to check
that it revolves absolutely smoothly. Repeat,
holding outer race and spinning inner race.
lRotate outer ring gently with a reciprocating
motion, while holding inner ring; feel for any
check or obstruction to rotation. Reject bearing
if action is not perfectly smooth.
lLubricate bearing with generous amounts of
lubricant appropriate to installation.
lInspect shaft and bearing housing for
discoloration or other markings which indicate
movement between bearing and seatings.
lEnsure that shaft and housing are clean and
free from burrs before fitting bearing.
lIf one bearing of a pair shows an imperfection, it
is advisable to replace both with new bearings;
an exception could be if the faulty bearing had
covered a low mileage, and it can be
established that damage is confined to only one
bearing.
lNever refit a ball or roller bearing without first
ensuring that it is in a fully serviceable condition.
lWhen hub bearings are removed or displaced,
new bearings must be fitted; do not attempt to
refit the old hub bearings.lWhen fitting a bearing to a shaft, only apply
force to the inner ring of the bearing. When
fitting a bearing into a housing, only apply force
to the outer ring of the bearing.
lIn the case of grease lubricated bearings (e.g.
hub bearings) fill the space between bearing
and outer seal with the recommended grade of
grease before fitting seal.
lAlways mark components of separable bearings
(e.g. taper roller bearings) when dismantling, to
ensure correct reassembly. Never fit new rollers
in a used outer ring; always fit a complete new
bearing assembly.