147
PART 2. MANUAL STEERING
SPECIFICATIONS
Steering gear type ............................ Rack and pinion
Steering column type ...................... Energy absorbing
collapsible and tilt adjustable
Steering wheel free play
(maximum ) ...................................................... 35 mm
Linkage........................... Direct from rack ends to t i e
rods and steering knuckles
Turns lock to lock ................................................. 3.6
Steering column length .................. 534.7-537.3 mm
Steering gear lubricant.............. Castrol EPL 1 grease
TORQUE WRENCH SETTINGS
Steering wheel retaining nut ............................ 39 Nm
Steering gear to bulkhead
mounting bolts .............................................. 108 Nm
Tie rod to steering knuckle nut...................... 98 Nm
Tie rod to tie rod end locknut ....................... 98 Nm
Tie rod ball housing to rack............................ 88 Nm
Steering column to mounting
bracket bolt ...................................................... 14 Nm
Steering column universal
coupling joint pinch bolts ............................... 29 Nm
2. STEERING WHEEL
Special Equipment Required:
To Remove Steering Wheel - Steering wheel
puller
TO REMOVE AND INSTAL
(1) Disconnect the negative battery terminal.
(2) Using a small screwdriver, carefully prise the
centre ornament from the steering wheel.
View of the steering wheel removed from the vehicle.
Steering wheels may vary between models.
1. DESCRIPTION
The steering gear is a rack and p i n i o n type
which is mounted on the lower section of the engine
compartment bulkhead by rubber mountings and
brackets.
The design of this assembly requires a range of
special tools to dismantle and assemble the steering
gear. If the steering gear is found to have a fault which
requires overhaul of the rack and pinion, it is recom-
mended that this be performed by an authorized work-
shop or steering specialist.
However, the procedures for the removal and
installation of the steering gear and the renewal of the
tie rods, the tie rod ends and the rubber boots are fully
covered in this section.
The rack and pinion assembly requires no lubri-
cation during service.
The steering column is of the energy absorbing
type designed to compress in the event of a severe
front end collision. The energy absorbing units are the
outer steering column, the tilt bracket and the steering
shaft. All these units shoul d be handled with extreme
care if service operations are performed on the
steering column assembly.
(3) Remove the steering wh eel retaining nut and
mark the steering shaft and steering wheel hub in
relation to each other as an aid to assembly.
(4) Remove the steering wheel from the steering
shaft.
NOTE: If the steering wheel will not sepa-
rate from the steering shaft, loosen the horn
pad retaining screws at the rear of the
steering wheel and withdraw the horn pad
after disconnecting the wire. A puller can
now be used to pull the steering wheel from
the steering shaft. Do not strike the end of
the steering shaft as sharp blows can cause
irreparable damage to the collapsible steer-
ing shaft.
(5) If necessary the steering wheel can be dis-
mantled as shown in the illustration.
Installation is a reversal of the removal procedure
with attention to the following points:
(1) Apply a light coat of multipurpose grease to
the horn slip ring and the turn signal canceling pins.
(2) Ensure that the marks on the steering wheel
and steering shaf t are aligned.
(3) Tighten the steering wheel retaining nut to
the specified torque.
Steering — Part 2 151
(8) Slide the rack out of the housing slightly so
that an adjustable spanner can be used to hold the
rack. (9) Using a Stillsons wrench, unscrew the ball
housings in turn using care not to allow the rack to
rotate. Keep all the tie rod parts in order. (10) Inspect the rack boots for cracks and deteri-
oration and renew as necessary. (11) Inspect the tie rod ends for wear and damage
and renew as necessary.
Dismantled view of the tie rod ball housing and the tie
rod end assemblies removed from the steering gear.
Assembly is a reversal of the dismantling proce-
dure with attention to the following points:
(1) Using large Stillsons and a large adjustable
spanner, install the tie rod and ball housing
assemblies
to the rack. Tighten the ball housings to the specified
torque.
NOTE: To avoid damage to the rack or
pinion the adjustable spanner must be
firmly tightened over the rack teeth and the
rack must not be allowed to rotate when
installing the ball housings.
(2) Measure a point 9 mm in from the rear face
of the ball housing of the rack and at 90 deg to the
rack teeth. Centre punch this point.
(3) At this point drill a 4 mm hole, 10 mm deep
through the rack and into the ball housing thread.
(4) Place a locking pin above the hole and drive
it into position.
(5) Lubricate the rack, rack teeth and t i e rod
boot groove with suitable EPL 1 grease. (6) Install the rack boots and secure with the
clamps. Renew the clamps if necessary. (7) Install the tie rod end locknuts and then the
tie rod ends, ensuring that they are screwed on the
same number of turns as was necessary to remove
them.
(8) Tighten the locknuts to the specified torque.
(9) Install the mounting rubbers and brackets
to
the steering gear as noted on removal. (10) Install the steering gear assembly to
the
vehicle as previously described. (11) Check and if necessary adjust the front wheel toe in as described in the Front Suspension section
under the appropriate heading.
TO RENEW TIE ROD END
(1)
Raise the front of the vehicle and support it
on chassis stands. (2) Remove the relevant front wheel.
(3) Loosen the tie rod end locknut and remove
the tie rod end castellated nut. Disconnect the tie rod
from the steering arm by plac ing a suitable dolly or
hammer against one side of the steering arm eye and
striking the opposite side with a hammer. (4) Unscrew the tie rod end from the tie rod,
noting the number of turns necessary to remove it.
(5) Screw the new tie rod end onto the t i e rod
the same number of turn s noted during removal.
(6) Connect the t i e rod to the steering arm and
install the castellated nut. Tighten the nut to the
specified torque and secure it with a new split pin.
(7) Install the front wheel and lower the vehicle
to the ground. (8) Check and if necessary, adjust the front
wheel toe in as described in the Front Suspension
section. Ensure that the rubber boots are not distorted
or twisted on the tie rod when the adjustment is
completed.
TO RENEW RUBBER BOOT
(1) Raise the front of the vehicle and support it
on chassis stands. (2) Remove the relevant t i e rod end as previ-
ously described. (3) Release the clamps securi ng the boot to the
tie rod and steering gear housing. (4) Unscrew and remove the locknut from the
tie rod. (5) Remove the rubber boot together with the
outer retaining clamp from the t i e rod. (6) Sparingly lubricate th e tie rod boot groove
with EPL 1 grease, install the new boot to the t i e
rod
and push it onto the steering gear rack housing. Install
and secure the inner and outer retaining clamps.
(7) Install the tie rod end locknut and screw
the
tie rod end onto the tie ro d the same number of turns
noted during removal. (8) Connect the tie rod to the steering arm and
install the castellated nut. Tighten the nut to the
specified torque and secure it with a new split pin. (9) Install the wheel and lower the vehicle to the
ground. (10) Check and if necessary, adjust the front
wheel toe in as described in the Front Suspension
section. Ensure that the rubber boots are not distorted
or twisted when the adjustment is completed.
170 Rear Suspension
6. KNUCKLE ASSEMBLY
TO REMOVE AND INSTAL
(1) Remove the rear hub as previously de-
scribed.
(2) On drum brake models, disconnect the brake
pipe from the wheel cylinder and plug the cylinder
and brake pipe apertures to prevent the loss of brake
fluid and the entry of dirt. (3) Remove the backing plate retaining bolts and
remove the backing plate from the knuckle assembly. (4) Remove the nut and bolt securing the control
arms to the knuckle assembly. (5) Remove the bolts and nuts securing the
suspension unit to the knuckle assembly. (6) Remove the nut, washers and bush securing
the stabilizer bar to the knuckle assembly, rotate the
knuckle assembly and remove it from the stabilizer
bar. (7) Carefully clean the knuckle assembly. Do not
immerse the rubber bush in solvent as damage will
occur.
(8) Check the knuckle assembly for wear, cracks
and damage. Installation is a reversal of the removal procedure
with attention to the following points:
(1) Install the knuckle assembly onto the stabi-
liser bar, maneuver it into position with the suspen-
sion unit and install the retaining bolts and nuts.
Tighten the bolts and nuts to the specified torque.
(2) Install the control arms to the knuckle
assem-
bly and install the retaining bolt and nut. Do
not
tighten the retaining bolt and nut at this stage. (3) Install the bush, washers and retaining nut to
the stabilizer bar. Do not tighten the retaining nut at
this stage. (4) Install the backing plate to the knuckle as-
sembly and tighten the retaining bolts to the specified
torque.
(5) On drum brake models, connect the brake
pipe to the wheel cylinder and tighten the flare nut
securely.
(6) Install the rear hub as previously described.
(7) On drum brake models, bleed the brake
hydraulic system as described in the Brakes section.
(8) With the weight of the vehicle on the road
wheels, tighten the control arms retaining bolt and nut
and the stabilizer bar retaining nut to the specified
torque. (9) Check and if necessary adjust the rear wheel
alignment. Refer to the Re ar Wheel Alignment head-
ing in this section.
7. STABILISER BAR
TO REMOVE AND INSTAL
(1) Raise the rear of the vehicle and support it
on chassis stands as describe d in the Wheels and Tires
section. Remove the rear wheels.
(2) Remove the nut. washer and bush retaining
the stabilizer bar to each knuckle assembly. (3) Remove the bolts retain ing the intermediate
exhaust pipe to the rear of the catalytic converter,
remove the bolt securing the exhaust mounting to the
underbody and slightly lower the intermediate exhaust
pipe. Support the intermediate pipe to prevent the
tailpipe contacting the lower bumper panel. (4) Remove the bolts retaining the stabilizer bar
mounting brackets to the underbody and withdraw
the stabilizer ba r from each knuckle assembly. Ma-
noeuvre the stabilizer bar from the vehicle.
(5) Remove the mounting rubbers from the
stabilizer bar and the rubber bush and spacer from
each knuckle assembly. (6) Inspect the stabilizer bar for cracks and
damage and renew as necessary. (7) Inspect the stabilizer bar mounting brackets
for wear and damage and renew as necessary. (8) Inspect the mounting rubbers, the rubber
bushes and spacers for wear and deterioration and
renew as necessary.
View of the knuckle assembly removed from the
vehicle. Disc brake model. View of the stabilizer bar mounting bracket and rubber
removed from the stabilizer bar.
172
BRAKES
SPECIFICATIONS
Type:
Except Pulsar/Vector GL from
July 1989 and Astra models ... Four wheel disc
Pulsar/Vector GL from
July 1989 and Astra models —
Front...............................................................Disc
Rear..............................................................Drum
Operation:
Footbrake ............... Vacuum assisted diagonally
split dual hydraulic
Handbrake................ Mechanical on rear wheels
Fluid type ...........................................................Dot 4
Master cylinder:
Make ........................................................ Girlock
Bore diameter —
Large .................................................... 25.40 mm
Small .................................................... 20.64 mm
Front disc brakes:
Caliper bore diameter ........................... 48.1 mm
Disc diameter ........................................ 240 mm
Disc thickness, minimum ......................... 16 mm
Disc runout, maximum ......................... 0.07 mm
Disc pad thickness, minimum ....................2 mm
Rear disc pads:
Caliper bore diameter ......................... 30.16 mm
Disc diameter ........................................ 234 mm
Disc thickness, minimum ...........................9 mm
Disc runout, maximum .......................... 0.07 mm
Disc pad thickness, minimum ....................2 mm
Rear drum brakes:
Wheel cylinder bore diameter ............ 15.87 mm
Drum diameter, maximum ............... 204.50 mm
Drum out of round, maximum.............. 0.03 mm
Drum runout, maximum ........................ 0.05 mm
Brake lining wear limit ........................... 1.5 mm
TORQUE WRENCH SETTINGS
Brake pedal bracket to body........................... 11 Nm
Brake pedal pivot bolt ..................................... 11 Nm
Brake servo unit to body................................. I I N m
Brake servo unit to master cylinder ............... 11 Nm
Pressure differential piston plug ...................... 12 Nm
Proportioning valve plug................................. 27 Nm
Caliper anchor plate bolts ............................... 52 Nm
Caliper guide bolts .......................................... 31 Nm
Brake hose to caliper....................................... 34 Nm
Handbrake cable bracket bolt ......................... 49 Nm
Handbrake lever to body ................................ 11 Nm
Cable clamp to body....................................... 11 Nm
Cam lever nut.................................................. 49 Nm
1. BRAKES TROUBLE SHOOTING
BRAKE PEDAL HARD
(1) Seized caliper piston or wheel cylinder: Over-
haul the caliper or wheel cylinder.
(2) Seized master cylinder piston: Overhaul the
master cylinder. (3) Seized pedal pivot: Rectify or renew the
pedal pivot shaft and bushes. (4) Restricted brake line: Remove the restriction
or renew the brake line.
(5) Vacuum servo system inoperative: Check
and repair the servo system.
NOTE: The vacuum servo system can be
checked as follows: With the engine
switched off, pump the brake pedal several
times to deplete any vacuum in the system.
With the engine still switched off, press
down firmly on the brake pedal and hold it
there noting the position and pressure re-
quired. Start the engine. If the servo unit is
operating correctly, the brake pedal will sink
slightly and the pressure required to hold it
may reduce. If the pedal does not sink
slightly when the engine is started, check the
vacuum supply to the servo unit. If vacuum
is reaching the brake servo unit, the unit can
be considered inoperative.
BRAKE DRAG
(1) Clogged master cylinder ports: Clean the
master cylinder and the fluid reservoir. Renew the
brake fluid. (2) Seized caliper piston or wheel cylinder: Over-
haul the caliper or wheel cylinder.
(3) Seized handbrake linkage: Free up or renew
the linkage.
Brakes 173
Inspect the handbrake cable for chafing or fraying.
(4) Seized handbrake cables: Renew the hand-
brake cables.
NOTE: Raise the vehicle and spin the
wheels one at a time to check for binding. If
the wheels are not binding, have an assistant
apply and release the brakes. Check if the
brakes release immediately. A clogged mas-
ter cylinder port will cause binding on the
two wheels fed by that particular circuit
from the master cylinder. Open the bleeder
valve on one of the o ffending wheels to check
if pressure build up is the cause of the
binding. A seized handbrake cable will usu-
ally cause binding on a rear wheel. Discon-
nect the handbrake cable and check if the
wheel will then turn freely.
LOW SPONGY BRAKE PEDAL
(1) Incorrectly adjusted brake shoes: Check and
adjust the brake shoes.
(2) Insufficient fluid in the system: Check for
leaks, replenish the fluid to the specified level and
bleed the hydraulic system.
(3) Air in the brake hydraulic system: Bleed the
hydraulic system. (4) Master cylinder faulty: Repair or renew as
necessary.
NOTE: A spongy brake pedal in most cases
is caused by air in the hydraulic system. For
air to enter the system one or more of the
sealing rubbers or brake lines must be
sucking in air. Always rectify the cause of
the trouble before bleeding the hydraulic
system. Faulty components usually show up
as fluid leakage.
BRAKES LOCK ON APPLICATION
(1) Gummy linings or brake pads due to oil or
fluid contamination: Renew the linings or brake pads
and rectify the source of contamination. (2) Scored or eccentric brake drum or warped
disc: Check and machine or renew the drum or disc as
necessary.
(3) Incorrect or distorted linings or disc pads:
Check and renew as necessary. (4) Brake servo unit faulty: Repair or renew the
brake servo unit. (5) Broken or stretched brake shoe return
springs: Check and renew th e faulty brake springs.
(6) Faulty brake pressure proportioning valve:
Renew the brake pressure proportioning valve.
NOTE: If this condition arises, remove all
the wheels and check the condition of the
friction material for oil contamination and
excessive wear. Check the shoe return
springs for stretching by comparing their
free length with new sp rings. An eccentric-
brake drum or warped disc will be indicated
by pulsating of the brake pedal when the
brakes are lightly applied.
BRAKE PEDAL PULSATES
(1) Eccentric brake drums or warped disc: Check
and machine or renew the drum or disc as required.
(2) Loose or worn hub bearings: Renew the hub
bearings as necessary.
NOTE: Brake drums or discs that are run-
ning out must be machined. This job is best
entrusted to a brake specialist who will also
be able to determine if a new disc or drum
needs to be installed.
BRAKE FADE
(1) Incorrect shoe adjustment: Check and adjust
the shoe to drum clearance. (2) Eccentric brake drum: Check and machine or
renew the brake drum.
Check the brake hoses for deterioration, chafing and
leaks.
Brakes 175
A pressure proportioning valve is incorporated in
each circuit to prevent premature locking of the rear
wheels during severe braking.
The four wheel hydraulically operated brakes
utilize disc brakes on each front wheel and disc brakes
or leading and trailing drum brake shoes on each rear
wheel.
The front disc brakes comprise a disc attached to
the hub assembly and a caliper bolted to the steering
knuckle.
The rear disc brakes comprise a disc and hub
assembly attached to the rear stub axle and a caliper
and anchor plate bolted to the backing plate.
The front and rear calipers are of the sliding type.
As pad wear takes place, the caliper piston is allowed
to slide outwards through the seal to take up a new
position in the caliper bore. Elastic deformation of the
seal takes place when the brakes are applied, which
returns the piston slightly when the brakes are re-
leased. Thus a constant clearance is maintained
between the pads and the disc when the brakes are in
the off position.
The disc brakes do not require periodical adjust-
ment in service to compensate for pad wear as they
are self adjusting.
The leading and trailing shoe drum brakes on the
rear wheels use a double ended wheel cylinder to
operate both brake shoes at the top. The lower end of
each brake shoe abuts a fixed anchor point. The brake
shoes are automatically adju sted when the brakes are
operated.
The handbrake operates the rear brakes via a
cable arrangement.
3. MASTER CYLINDER
Special Equipment Required:
To Install New Seals — Suitable machined drift
TO REMOVE
(1) Depress the brake pedal several times to
deplete the vacuum from the system.
(2) Raise the bonnet and install covers to
both
the front mudguards. Cover the areas of paintwork
beneath the master cylinder with absorbent cloth.
(3) Disconnect the wiring from the pressure
sensing switch. (4) Disconnect the brake pipes from the master
cylinder and plug the outlets and pipes to prevent the
loss of fluid and the ingress of dirt.
(5) Remove the nuts retaining the master cylin-
der to the brake servo unit and remove the master
cylinder from the vehicle.
TO DISMANTLE
(1) Remove the master cylinder as previously
described. (2) Remove the reservoir cap and diaphragm,
drain and discard the brake fluid from the reservoir. (3) Carefully remove the reservoir from the
master cylinder by pulling it from the reservoir
retainers by hand. Remove and discard the retainers
from the master cylinder. (4) Using internal snap ring pliers, remove the
snap ring from the primary reservoir port. (5) Remove the fast fill valve assembly and the
O ring from the port. Remove and discard the valve
washer from the fast fill valve.
(6) Remove the proportioning valve plugs and
the O rings. Discard the O rings. Withdraw the springs
and valve plungers from the master cylinder. Remove
and discard the seals from the valve plungers. (7) Remove the pressure sensing switch and
lever assembly from the master cylinder. {8) Remove the cylinder end plug from the
master cylinder. Remove and discard the O ring from
the plug.
(9) Carefully tap the front of the master cylinder
vertically on a block of wo od and remove the pressure
differential pistons from the master cylinder. Remove
and discard the O rings from the pistons. (10) Push the primary piston forward in the
cylinder with a blunt rod and while holding the
pressure, remove the stop pin from the master cylin-
der.
(11) The primary piston may now be withdrawn
from the cylinder bore. The secondary piston, retainer
and spring can also be withdrawn by carefully tapping
the master cylinder on a block of wood. (12) Prise the legs of the seal retainer upwards
and remove it from the primary piston. Remove the
seal and guide. Discard the seal and retainer.
NOTE: The secondary piston must no! be
dismantled by removing the screw. This
assembly has a factory p reset length and the
screw must not be altered in service.
(13) Remove the main seal and the guide from
the front of the secondary piston. Stretch the rear seal
from the groove and remove it from the piston. Take
Installed view of the master cylinder and servo unit. Air
duct removed for clarity. 1.8 liter model.
176 Brakes
care not to damage the piston surfaces where the inner
diameter of the piston seals locate.
(14) Remove the garter springs, back up rings,
seals and the retainer from the master cylinder, noting
the installed direction of the seals to aid assembly.
NOTE: It is important that care is taken not
to damage the bore surface or the seal
surfaces during removal of these parts. Note
the order and direction during removal,
(15) Remove the external O ring from the master
cylinder body.
TO CLEAN AND INSPECT
(1) Wash all components thoroughly in methyl-
ated spirits. Do not use petrol, kerosene or other
cleaning solvents. (2) Check the master cyli nder bore for wear,
scoring or pitting.
NOTE: Do not hone the master cylinder
bore. If the bore is pitted or worn, renew the
master cylinder as an assembly.
(3) Ensure that all the inlet and compensating
ports between the reservoir and the cylinder bore are
free of any obstructions.
(4) Discard all rubber parts and if applicable, the
piston assemblies.
NOTE: Where possible use a genuine major
repair kit which contains pre-assembled rub-
ber seals and pistons when overhauling a
master cylinder. The use of a major kit will
ensure a thorough overhaul and long service
from the unit.
TO ASSEMBLE
(1) Liberally coat the cylinder bore and all
internal parts with clean brake fluid.
NOTE: Install all parts supplied with the
repair kit.
(2) Install the seal retainer in the mouth of
the
master cylinder, small diameter first.
(3) Install the seal, in the direction rioted
on
removal, against the seal retainer, followed by the first
back up ring, large diameter first. (4) Install the garter spring against the back up
ring. Insert a machined drift into the bore and lightly
push the garter spring into its locating groove. (5) Install the remaining seal, in the
direction
noted on removal, against the garter spring already
PRIMARY PISTON SEAL
BACK UP RING
Dismantled view of the master cylinder.
Brakes 177
installed. Install the second back up ring, large
diam-
eter first.
(6) Install the second garter spring. Insert
a
machined drift into the bore and lightly push the
garter spring into its locating groove.
(7) Smear the secondary piston with clean brake
fluid. Ease the seal over the piston body into the
groove adjacent to the spring, ensuring that the seal lip
faces the spring and that the nylon spacer is against
the back of the seal. (8) Install the guide onto the secondary
piston,
large internal diameter first, followed by the main seal
with the lip facing away from the spring. (9) Lubricate the secondary piston assembly
with clean brake fluid and install the secondary spring
and retainer to the piston. Install the complete assem-
bly into the master cylinder bore. (10) Smear the primary piston with clean brake
fluid. Install the guide, large internal diameter first,
followed by the main seal with the lip facing towards
the small end of the piston.
(11) Install the retainer to the spigot on the front
end of the primary piston ensuring that the legs of the
retainer engage with the groove on the piston. (12) Lubricate the primary piston assembly with
clean brake fluid and install the assembly into the
master cylinder bore. With a blunt rod, push the
assembly down the bore sufficiently to preload the
pistons. While holding the preload, install the stop pin
and valve assemblies into
the master cylinder body and tighten securely. (13) Install a new O ring to the groove on the boss
of the mounting flange of the master cylinder.
(14) Install new O rings to th e pressure differential
pistons, smear them with cl ean brake fluid and install
them into the master cylinder body. (15) Install a new O ring to the pressure differen-
tial end plug, install the plug to the master
cylinder
body and tighten to the specified torque. (16) Using a blunt probe entered through the
sensing switch location hole, separate the pressure
differential pistons and install the switch actuating
lever between them. (17) Screw the sensing switch into its locating
hole until the detents on the switch body just contact
the locating hole facing (w ith the radial grooves).
Screw the switch assembly in a further half to one full
turn ensuring that the dete nts locate in the grooves.
(18) Install new valve seal s to the proportioning
valve plungers, with the serrations of the seals facing
away from the hexagons of the plungers.
(19) Install the new O rings to the
proportioning
valve plugs. (20) Install the valve springs over the stems of the
proportioning valves, insert the install the valve
plugs.
Tighten the plugs to the specified torque.
(21) Install a new O ring to the base of the fast fill
valve assembly. Install a new valve washer to the base
of the valve.
(22) Install the fast fill valve assembly in
the
primary reservoir port (nearest to the mounting flange
of the master cylinder) and install the snap ring
to
retain the assembly. Ensure that the snap ring is
correctly seated in the groove. (23) Smear the new reservoir retainers with clean
brake fluid and install them into the reservoir ports.
Carefully press the brake fluid reservoir into position,
ensuring that the outlet extensions are fully inserted in
the reservoir retainers. (24) Install the reservoir cap insert to the dia-
phragm and press the cap assembly onto the reservoir.
TO INSTAL
Installation is a reversal of the removal procedure
with attention to the following points:
(1) Pour a small amount of clean brake fluid into
the reservoir and pump the master cylinder pistons
with a blunt rod until fluid begins to emerge from the
outlets. (2) Install the master cylinder to the brake servo
unit and loosely install the master cylinder retaining
nuts. (3) Connect the brake pipes to the master cylin-
der outlets, but do not tighten at this stage. (4) Securely tighten the nuts retaining the master
cylinder to the brake servo unit.
(5) Securely tighten the brake pipes and connect
the wiring to the pressure sensing switch.
(6) Fill the master cylinder reservoir with clean
brake fluid and bleed the brakes as described under
the Hydraulic System heading. (7) Check and if necessary adjust the brake
pedal height and free play as described under the
Brake Pedal heading.
4. BRAKE SERVO UNIT
TO CHECK OPERATION
(1) With the engine switched off, apply the
footbrake several times to exhaust all vacuum from
the system.
(2) Apply the footbrake and hold the brake pedal
fully depressed.
(3) Start the engine. If the servo unit is function-
ing satisfactorily a distinct downward movement of
the
brake pedal should be noticed. Should the pedal fail to move downward when the
engine has been started, the vacuum system can be
considered inoperative.
NOTE: If the pedal continues to fall away
there is a fault in the hydraulic system.
(4) Ensure that the brake pedal is fully released,
start the engine and run it at medium speed. Stop the
engine.