Discovery 2. Manual — part 634

BRAKES

DESCRIPTION AND OPERATION

70-27

Drum brake

1 Drum
2 Drum securing bolt
3 Backplate
4 Cable
5 Backplate securing bolt

The drum brake consists of a backplate attached to the transfer box casing and a drum attached to the transfer box
rear output shaft. When the handbrake lever is applied, the movement is transmitted by the inner cable to a lever on
one of the brake shoes on the backplate. The lever pivots against the brake adjuster rod, which forces the shoes apart
and into contact with the drum. Brake shoe to drum clearance is set by an adjusting bolt on the rear of the backplate.

BRAKES

70-28

DESCRIPTION AND OPERATION

BRAKES

ADJUSTMENTS

70-29

ADJUSTMENTS

Handbrake

$% 70.45.09

Check

1. Apply the handbrake lever 3 notches on the

ratchet. The handbrake should be fully
operational.

2. If the handbrake is not fully operational, the

brake shoes and/or the handbrake cable need
adjusting.

Adjust

1. Raise rear of vehicle.

WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.

2. Ensure handbrake lever is fully released.

3. Tighten brake shoe adjusting bolt until brake

drum is locked, then back off adjusting bolt 1.5
turns. Check that the brake drum is free to
rotate.

4. Recheck handbrake operation.If handbrake is

not fully applied with 3 notches on the
ratchet, the handbrake cable requires
adjustment.

5. Remove switch panel from centre console.

+

WINDOWS, REPAIRS, Switch -

console.

6. Release handbrake lever gaiter from centre

console.

7. Rotate adjuster anti-clockwise to increase

cable tension (reduce notches) or clockwise to
decrease cable tension (increase notches).

8. Recheck handbrake operation.
9. Secure handbrake lever gaiter to centre

console.

10. Fit switch panel to centre console.

+

WINDOWS, REPAIRS, Switch -

console.

11. Remove stand(s) and lower vehicle.

BRAKES

70-30

ADJUSTMENTS

Brake system bleeding

$% 70.25.02

Bleeding of the brake system can be carried out
using the procedures given on TestBook, or by
following the manual procedure given below.

WARNING: If any components upstream of brake
modulator, including the modulator itself are
replaced, the brake system must be bled using
the procedure on TestBook/T4, to ensure that all
air is expelled from the new component(s).

WARNING: Do not allow brake fluid to come into
contact with eyes or skin.

Bleed

NOTE: This procedure covers bleeding the
complete system, but where only the primary or
secondary circuit have been disturbed in
isolation, it should only be necessary to bleed
that circuit. Partial bleeding of the hydraulic
system is only permissible if a brake pipe or
hose has been disconnected with only minor
loss of fluid.

1. Do not allow fluid level in master cylinder to fall

below 'MIN' mark during bleeding.

2. Do not fill reservoir above 'MAX' level.
3. Raise front and rear of vehicle.

WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.

4. Check all pipe and hose connections are tight

and there are no signs of leakage.

5. Top-up fluid level in brake reservoir to 'MAX'

mark.

WARNING: Do not allow dirt or foreign
liquids to enter the reservoir. Use only new
DOT 4 brake fluid from airtight containers.
Do not mix brands of brake fluid as they
may not be compatible.

6. Attach bleed tube to the bleed screw on front

brake caliper on the passenger side, submerge
free end in a clear container containing brake
fluid.

7. Apply pressure to brake pedal several times,

then apply steady pressure.

8. Loosen bleed screw to release brake fluid and

air. Allow pedal to return unassisted.

9. Depress brake pedal steadily through its full

stroke and allow to return unassisted. Repeat
procedure until a flow of clean air-free fluid is
purged into container then, whilst holding
pedal at end of downward stroke, tighten brake
caliper bleed screw to 10 Nm (7 lbf.ft).

CAUTION: Ensure the fluid in the reservoir
is maintained between the minimum and
maximum levels throughout the bleed
procedure using new brake fluid.

10. Top-up brake fluid level to 'MAX' mark.