Defender (1993+). Manual — part 83

BRAKING

SYSTEM

Fitting

8.

Make sure that disc and hub mating faces are

clean and free

from

burrs or any other

irregularities that could cause the disc to run

out

excessively.

9.

Assemble the disc to the hub with the five
bolts and tighten evenly to the correct torque.

12. Continue with instructions 32

to

41,

SECTION

54.

10.

Fit

the hub and disc assembly to the axle by

following instructions 24

to

31,

SECTION

54.

11. Mount the dial test indicator bracket

RO

530106 or a suitable alternative on the top
swivel and rest the stylus

of

the dial indicator

on the disc face near to the periphery. The
maximum run out must not exceed 0,151 mm.

BRAKING SYSTEM

OVERHAUL MASTER CYLINDER - Lucas Girling -

Type 25.4 mm AS/AS

Dismantling master cylinder

1.

Disconnect the battery and remove the master

cylinder from the servo.

WARNING: Use only clear methylated spirit or
unused brake fluid to clean all parts of the brake
system. DO NOT use petrol, kerosene or other
mineral based fluids.

2.

Before commencing the overhaul procedure

thoroughly clean the master cylinder and

6.

Withdraw the two reservoir seals from the

inspect the outer surfaces for damage and

master cylinder inlet ports the seals are

condition, renew the complete assembly if

different and should be noted for assembly,

necessary.

discard both of the seals.

3.

The reservoir is a push fit in the master

7. Remove the retaining ring and ' O ' ring seal

cylinder and secured by seals. Carefully ease

from the machined outer surface

of

the master

the reservoir from the master cylinder by

cylinder, discard both the seal and retaining

rolling it from the seals as illustrated.

ring.

4.

Using

soft

jaws,

one either side of the master

cylinder flange and clamp the flange in a
suitable vice. Remove the water ingress ' O '

ring seal from the master cylinder

to

servo

flange and discard.

5.

Hold the outside of the transfer housing with a
suitable pair of grips, carefully pull, while

working the pliers in a backwards and
forwards rocking motion to ease the housing

off

the master cylinder, discard the housing

and vacuum seal.

KEY TO MASTER CYLINDER

1.

Water ingress seal

10. Washer

2.

Transfer housing

11.

Recuperating seal (primary cup)

3.

Vacuum seal

12. Seal retainer

4. Guide ring

13. Springs (2 off)

5.

Retaining ring

14. Swirl tube

6. 'O' ring seal

15. Master cylinder body

7. Primary plunger assembly

16. Reservoir seals

8. 'L' seal

17. Reservoir

9.

Secondary plunger

18. Low fluid level switch and cap

BRAKING SYSTEM

Assembling master cylinder

21.

Fit a new retaining ring on the outer surface

of the master cylinder ensuring that the

CAUTION: It is important that the following

serrations of the ring are facing the mounting

instructions are carried out precisely, otherwise

flange.

damage could be caused to the new seals when

22.

Fit the two new reservoir seals in their

23. Fit a new vacuum seal

to

either the primary

used to lubricate the parts during assembly.

plunger or to the bottom of the transfer
housing bore, open face of the seal towards
the primary plunger guide ring.

is essential.

24. Lubricate the vacuum seal with brake fluid, fit

the transfer housing to the master cylinder,

Also thoroughly check that n o debris of any

push the housing fully up to the cylinder

description is lodged in any of the fluid

mounting flange.

DO

NOT ADJUST THE

passageways and drillings. If debris is found,

TRANSFER HOUSING AFTER FITTING.

carefully remove, clean the cylinder and re-check.

25. Lubricate a new water ingress seal with brake

fluid, slightly stretch the seal and ease it down

16.

Fit the new swirl tube to the bottom of the

the housing until the seal

is

in the correct

cylinder bore.

position between the housing and flange.

17.

Lubricate the secondary plunger and cylinder

26.

Roll the reservoir into the top

of

the master

bore. Offer the plunger assembly to the

cylinder, reversing the procedure described in

cylinder until the recuperation seal is resting

instruction 3.

centrally in the mouth of the bore. Gently

27. Fit the master cylinder to the servo, connect

introduce the plunger with a circular rocking

the battery, and road test the vehicle.

motion, as illustrated. Ensuring that the seal

does not become trapped, ease the seal into
the bore and slowly push the plunger down
the bore in one continuous movement.

inderting the plungers into the cylinder bore.

respective ports.

Generous

amounts

of new brake fluid should be

Never use old fluid or any other form of cleaning

and lubricating material. Cleanliness throughout

18.

Fit the primary plunger assembly using the

same method as for the secondary plunger,
push the plunger down the bore.

19.

Fit the original guide ring to support the

primary plunger.

20. Coat a new ' O ' ring with brake fluid and fit

to

its respective groove on the outer location
surface

of

the master cylinder.

NOTE: The ' O ' ring should not be rolled down
the

outer location surface of the master cylinder

but should be slightly stretched and eased down

the cylinder and into

its

groove. Do not over

stretch the seal.