service LAND ROVER DEFENDER 1996 Workshop Manual

70BRAKES
2
REPAIR BRAKE SYSTEM BLEED
Service repair no - 70.25.02
Preparation
WARNING: Before bleeding the brake
system refer to general brake service
practice.
See General Brake Service
Practice
.
·During bleed procedure, brake fluid level must
not be allowed to fall below the MIN level.
·To bleed the hydraulic circuits, four bleed
nipples are provided, one at each caliper.
·There are two methods by which air can be
removed from the braking system:-
1. MANUAL BLEED PROCEDURE.
2. PRESSURE BLEED PROCEDURE.
Pressure bleed procedure
Purpose designed equipment for pressure filling and
bleeding of hydraulic systems may be used on Land
Rover vehicles. The equipment manufacturer's
instructions must be followed and the pressure must
not exceed 4.5 bar, 65 lb/in
2.
Manual bleed procedure
Equipment required
·Clean glass receptacle
·Bleed hose
·Wrench
·Approx 2 litres (3 pints) brake fluid.
See
LUBRICANTS, FLUIDS AND CAPACITIES,
Information, Recommended lubricants and
fluids
Master cylinder bleed
1.Disconnect battery.
2.Depress brake pedal fully and slowly 5 times.
3.Release the pedal and wait for ten seconds.
4.Air bubbles will rise into the reservoir during
these instructions.
5.Repeat instructions until a firm resistance is felt
at the pedal.
Complete circuit bleed
1.Disconnect battery.
2.Bleed front calipers, driver's side first. Fit bleed
hose to bleed screw.
3.Dip free end of bleed hose into brake fluid in
bleed bottle.
4.Open bleed screw of caliper.
5.Depress brake pedal fully several times until fluid
is clear of air bubbles.
6.Keeping pedal fully depressed, tighten bleed
screw, then release pedal.
7.Repeat procedure on other front caliper followed
by rear calipers.
8.Fit all bleed screw protection caps.
9.Check/top-up fluid level when bleeding is
complete
See Fluid Level Check/Top-Up.

BRAKES
3
REPAIR MASTER CYLINDER
Service repair no - 70.30.08
Before starting repair refer to general brake service
practice
See General Brake Service Practice.
Remove
1.Disconnect battery.
2.Place a container under the master cylinder to
catch escaping brake fluid.
3.Clean area round master cylinder ports.
4.Disconnect pipes from master cylinder ports.
Cover, not plug, the pipe ends to prevent entry of
dirt.
5.Disconnect electrical leads from reservoir cap.
6.Remove two nuts securing master cylinder to
servo and withdraw cylinder.
7.Remove reservoir cap and drain fluid into
suitable container for disposal.
8.The reservoir is a push fit in the master cylinder
and secured by seals. Carefully ease the
reservoir from the master cylinder by rolling it
from the seals. Note that the two seals are
different sizes.
Refit
9.Insert new reservoir seals in the master cylinder
ports and fit reservoir to master cylinder.
10.Ensuring that water ingress seal is in position, fit
master cylinder to servo. Tighten fixings to
26
Nm (19 lbf/ft).
11.Connect brake pipes to master cylinder ports
and tighten to
15 Nm (11 lbf/ft).
12.Fit electrical leads to reservoir cap
13.Fill reservoir with recommended brake fluid.
See
LUBRICANTS, FLUIDS AND CAPACITIES,
Information, Recommended lubricants and
fluids
14.Bleed the brake systemSee Brake system
bleed
.
15.Reconnect battery and road test vehicle.

70BRAKES
4
REPAIR PRESSURE REDUCING VALVE (PRV)
Service repair no - 70.25.21
Remove
1.Disconnect battery.
2.Clean area around reducing valve ports.
3.Place a container under valve to catch escaping
brake fluid.
4.Disconnect primary circuit pipe unions ñAñ
from valve.
5.Disconnect secondary circuit pipe unions ñBñ
from valve.
6.Cover pipes to prevent ingress of dirt.
7.Remove single retaining nut and bolt securing
valve to engine bulkhead.
8.Remove valve.
Refit
9.Fit valve to engine bulkhead. Tighten bolt to
15
Nm (11 lbf/ft).
10.Connect primary and secondary circuit pipes to
valve. Tighten to
16 Nm (12 lbf/ft).
11.Fill brake reservoir with recommended brake
fluid
See LUBRICANTS, FLUIDS AND
CAPACITIES, Information, Recommended
lubricants and fluids
.
12.Bleed the brake system
See Brake system
bleed
.
13.Reconnect battery and road test vehicle.SERVO NON RETURN VALVE
Service repair no - 70.50.15
Remove
1.Disconnect brake vacuum hose from servo non
return valve.
2.Carefully prise valve out with a screwdriver blade
between valve and grommet. Take care not to
exert too much pressure on the vacuum
chamber.
3.Remove rubber grommet but be careful not to
allow it to fall into the vacuum chamber.
4.Check the valve for correct operation; it should
not be possible to pass air through into the servo
in direction of arrow. Do not use compressed air.
Refit
5.Fit rubber grommet.
6.Smear ribs of the valve with Lucas Girling rubber
grease to assist assembly, and push valve fully
home.
7.Connect vacuum hose to the valve.
8.Road test vehicle.

BRAKES
5
REPAIR SERVO ASSEMBLY
Service repair no - 70.50.01
Remove
Before starting repair refer to general brake service
practice
See General Brake Service Practice.
NOTE: The non-return valve and grommet,
are the only serviceable components. In
event of failure or damage, fit a new unit.
1.Remove master cylinderSee Master cylinder.
2.Disconnect vacuum supply hose from servo unit.
3.At footwell, release 2 brake pedal return springs.
4.Disconnect leads from brake light switch at rear
of pedal box.
5.Remove blanking grommets from each side of
pedal box.
6.Remove split pin and clevis pin securing servo
push rod to brake pedal.
7.Remove 4 nuts and plain washers securing
servo to pedal box.
8.Remove servo assembly and rubber washer
from bulkhead.Refit
9.Locate servo assembly and rubber washer to
engine bulkhead and secure to pedal box.
Tighten fixings to
14 Nm (10 lbf/ft).
10.Fit brake pedal to servo push rod with clevis pin
and new split pin.
11.Fit blanking grommets to each side of pedal box.
12.At footwell, attach pedal return springs.
13.Connect vacuum hose to servo non-return valve.
14.Fit brake master cylinder to servo unit
See
Master cylinder
.

70BRAKES
6
REPAIR BRAKE PEDAL
Service repair no - 70.35.01 - Brake pedal
Service repair no - 70.35.03 - Pedal box
Remove
1.Remove brake servo assembly.
See Servo
assembly
.
2.Remove 6 bolts securing pedal box to engine
bulkhead.
3.Taking care not damage brake fluid pipes,
remove pedal box assembly and gasket.
4.Release return springs from pedal and pedal box
bosses.
5.Using a suitable punch, drift out retaining pin and
withdraw pedal pivot shaft.
6.Remove brake pedal complete with pivot
bushes.
7.Examine components for wear or damage,
renew as necessary.
8.If it is necessary to fit new pivot bushes, they
must be reamed out to 15,87 mm±0,02 mm
(0.625±0.001 in) after fitment.Refit
9.Lubricate pedal pivot shaft and bushes with
general purpose grease.
10.Fit pedal to pedal box, insert pivot shaft and
secure with new split pin.
11.Attach return springs to pedal and pedal box
bosses.
12.Fit pedal box and gasket to engine bulkhead.
Tighten fixings to
25 Nm (18 lbf/ft).
13.Fit brake servo assembly.See Servo
assembly
.

BRAKES
7
REPAIR REV: 05/99 FRONT BRAKE PADS - ALL MODELS
Service repair no - 70.40.02
Remove
1.Remove front road wheels .
2.Clean exterior of calipers.
3.Remove split pin from retaining pins.
4.Remove pad retaining pins and anti-rattle
springs.
5.Remove brake pads.
6.Clean exposed parts of pistons, using new brake
fluid. Wipe away excess with a lint free cloth.
7.Using piston clampLRT-70-500press each
piston back into its bore. Ensure that displaced
brake fluid does not overflow from reservoir.
Refit
8.Fit brake pads.
9.Fit pad retaining pins and anti-rattle springs.
Secure with new split pins.
10.Apply service brake pedal several times to locate
pads.
11.Fit road wheels. Tighten wheel nuts to correct
torque:
Alloy wheels -
130 Nm (96 lbf/ft)
Steel wheels -100 Nm (80 lbf/ft)
Heavy duty wheels -170 Nm (125 lbf/ft)
12.Check fluid reservoir. Top up if necessary, using
correct grade of fluid
See LUBRICANTS,
FLUIDS AND CAPACITIES, Information,
Recommended lubricants and fluids
.

70BRAKES
8
REPAIRREV: 05/99 REAR BRAKE PADS
Service repair no - 70.40.03
Service tool:
Remove
1.Remove rear road wheels.
2.Clean exterior of calipers.
3.Remove pad retaining pins and anti-rattle
springs. Note differences between 90 and
110/130 models.
4.Remove brake pads.
5.Clean exposed parts of pistons, using new brake
fluid. Wipe away excess with a lint free cloth.
6.Using piston clampLRT-70-500press each
piston back into its bore. Ensure that displaced
brake fluid does not overflow from reservoir.
Refit
7.Insert brake pads.
8.Fit anti-rattle springs and secure with retaining
pins.
9.Apply service brake pedal several times to locate
pads.
10.Fit road wheels, remove chassis stands and
jack. Tighten wheel nuts to correct torque:
Alloy wheels -
130 Nm (96 lbf/ft)
Steel wheels -100 Nm (80 lbf/ft)
Heavy duty wheels -170 Nm (125 lbf/ft)
11.Check fluid reservoir, top up if necessary, using
correct grade of fluid
See LUBRICANTS,
FLUIDS AND CAPACITIES, Information,
Recommended lubricants and fluids
.
90 Models
110/130 Models

70BRAKES
10
REPAIR FRONT BRAKE CALIPERS
Service repair no - 70.55.05
Service repair no - 70.55.16
Before starting repair refer to general brake service
practice
See General Brake Service Practice.
Remove
1.Remove front road wheels.
2.Expose flexible brake hose by moving coiled
protective covering.
3.Using a recognised hose clamp, clamp hose to
prevent loss of brake fluid.
4.Disconnect rigid brake pipe from flexible hose,
seal exposed ends to prevent ingress of dirt.
5.Remove split pin, retaining pins and springs,
withdraw pads. If refitting pads, identify them for
assembly to original locations.
6.Remove 2 bolts and withdraw caliper from swivel
housing.
WARNING: Do not separate caliper halves
7.Clean outer surfaces of caliper using aerosol
brake cleaner.
8.Using special toolLRT-70-500, clamp pistons in
inboard half of caliper. Gently, keeping fingers
clear, and withCAUTION, apply air pressure to
fluid inlet port to expel pistons. It is unlikely that
pistons will expel at same time, regulate rate
with a suitable piece of wood between
appropriate piston and caliper.
9.Finally remove pistons, identifying them with
their respective bores.
10.Remove wiper seal retainer by inserting a blunt
screwdriver between retainer and seal. Pry
retainer carefully from mouth of bore.
11.Taking care not to damage seal grooves, extract
wiper seal and fluid seal.
12.Clean bores, pistons and seal grooves using
clean brake fluid only. If caliper or pistons are
corroded, or their condition is not perfect, new
parts must be fitted.

BRAKES
11
REPAIR REV: 05/99 Assemble outboard pistons
13.Coat new fluid seal with brake fluid. Ease seal
into groove in bore using only fingers, ensuring it
is properly seated. Fluid seal and groove are not
same in section, so when seal is seated it feels
raised to touch at edge furthest away from
mouth of bore.
14.Coat appropriate piston with brake fluid. Insert it
squarely into bore by hand only. Do not tilt piston
during insertion, leave approximately 8mm
projecting from bore.
15.Coat new wiper seal with brake fluid and fit to
new seal retainer. Slide assembly, seal first, over
protruding piston and into bore recess. Use
piston clamp to press home seal retainer and
piston.
Mounting inboard pistons
16.Clamp outboard pistons and carry out same
procedure for removing and fitting outboard
pistons and seals, instructions 8 to 15.
Fit calipers and pads
17.Fit caliper, tighten bolts evenly to
82 Nm (60
lbf/ft).
18.Connect brake flexible hoses to caliper. Tighten
to
15 Nm (11 lbf/ft).
19.Remove hose clamps.
20.Insert pads. Fit pins and springs, secure using
new split pin.
21.Bleed brake system
See Brake System Bleed
.
22.Press brake pedal firmly several times to locate
friction pads.
23.Fit road wheels, remove axle stands. Finally
tighten road wheel nuts to correct torque:
Alloy wheels -
130 Nm (96 lbf/ft)
Steel wheels -100 Nm (80 lbf/ft)
Heavy duty wheels -170 Nm (125 lbf/ft)
24.Road test vehicle. Note that new friction pads
require 'bedding-in', this may take several
hundred miles before brakes are at maximum
efficiency.FRONT BRAKE DISCS
Service repair no - 70.10.10.
Remove
1.Remove hub assembly
See FRONT AXLE AND
FINAL DRIVE, Repair, Front hub assembly
.
2.Remove 5 hub to disc bolts.
3.Tap disc to separate from hub.
NOTE: On 110/130 vehicles ventilated
discs are fitted as standard.
Refit
4.Locate disc to hub.
5.Apply Loctite 270 to disc bolts and tighten to
73
Nm (54 lbf/ft).
6.Check total disc runout with a dial indicator, this
must not exceed 0,15 mm, 0.006 in. If necessary
reposition disc.
7.Fit hub assembly
See FRONT AXLE AND
FINAL DRIVE, Repair, Front hub assembly
.
Disc reclamation
8.Check disc thickness. This dimension may be
machined to minimum thickness of 12 mm (0.47
in.) - solid discs, 22 mm (0.90 in) - ventilated
discs. Machine equal amount off each face.
NOTE: The disc MUST BE renewed if the
minimum running thickness stamped on
the disc is recorded.

BRAKES
13
REPAIR REAR BRAKE CALIPERS
Service repair no - 70.55.06
Service repair no - 70.55.17
Before starting repair refer to General brake service
practice
See General Brake Service Practice.
Remove caliper
1.Remove rear road wheels.
2.Using a recognised hose clamp, clamp flexible
brake hose above rear axle.
90 Models
110/130 Models
3.Remove brake pipe from rear brake caliper.4.Seal pipe ends to prevent ingress of dirt.
5.Remove retaining pins and springs and withdraw
pads. If same pads are to be refitted, identify
them for assembly in original positions.
6.Remove 2 bolts and withdraw caliper from rear
axle.
Repair
WARNING: Do not separate caliper halves.
7.Clean outer surfaces of caliper with aerosol
brake cleaner.
8. WITH CAUTIONexpel pistons from their bores
by applying air pressure to fluid inlet port. It is
unlikely both pistons will expel at same time,
regulate rate with a suitable piece of wood
inserted between two pistons.
9.Finally, remove pistons keeping them identified
with their respective bores.
10.Remove wiper seal retainer by inserting a blunt
screwdriver between retainer and seal and pry
retainer carefully from mouth of bore.
11.Taking care not to damage seal grooves, extract
wiper seal and fluid seal.
12.Clean bores, pistons and particularly seal
grooves using clean brake fluid only. If caliper or
pistons are corroded or their condition is not
perfect new parts must be fitted.
13.Apply brake fluid to new seal. Fit seal into
groove in bore. When seal is seated it feels
raised to touch at edge furthest away from
mouth of bore.
14.Coat piston with brake fluid. Insert it squarely
into bore. Do not tilt piston during insertion and
leave 8mm projecting from bore.