Nissan PULSAR N13 Series / ASTRA LD Series. Manual — part 44

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 the pressure differential

pistons, smear them with clean 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 (with the radial grooves).
Screw the switch assembly in a further half to one full
turn ensuring that the detents locate in the grooves.

(18) Install new valve seals 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.

178

Brakes

Let the vehicle stand for 1-2 minutes, press the

brake pedal two or three times and check its opera-
tion.

If there is no vacuum assistance, the vacuum

system has developed a leak or the one way check
valve is defective.

NOTE: Before removing the servo unit from
the vehicle for inspection, disconnect the
hose from the servo unit, start the engine
and check that the manifold vacuum is in
fact reaching the servo unit. Also test the one
way check valve as described below,

TO TEST ONE WAY CHECK VALVE

(1) Disconnect the hose and remove the check

valve from the servo unit.

(2) Check the valve for sticking. Suction on the

manifold side should allow air to flow freely. Air
blown into the valve from the manifold side should
not be able to flow through the valve.

(3) Install the valve and check the operation

of
the servo unit as previously described.

NOTE: Check that there are no air leaks at
the hose connections and that the hose clips
are tight. Also check that the hose is not
bulged or collapsed due to deterioration.

Checking for vacuum at the servo unit. The engine

must be running for this test.

TO REMOVE

(1) Raise the bonnet and install covers to both

front mudguards.

(2) On 1.6 liter models, remove the air cleaner

assembly from the vehicle. If necessary refer to the
Fuel System section.

(3) On vehicles equipped with power steering,

remove the reservoir from the bulkhead and move it
to one side. If necessary refer to the Steering section.

(4) Disconnect the vacuum supply hose from the

servo unit.

View of the brake servo unit and associated compo-

nents.

(5) Remove the master cylinder as described

under the Master Cylinder heading.

(6) Working inside the vehicle, remove the clip

and clevis pin connecting the pushrod to the brake
pedal.

(7) Remove the nuts retaining the servo unit to

the bulkhead and maneuver the servo unit and
spacer block from the vehicle.

TO INSTAL

Installation is a reversal of the removal procedure

with attention to the following points:

(1) With the servo unit and master cylinder

installed to the vehicle, bleed the hydraulic system as
described under the Hydraulic System heading.

(2) Check and if necessary adjust the brake

pedal height and free play as described under the
Brake Pedal heading.

5. FRONT BRAKES

Special Equipment Required:

To Check Disc Runout — Dial gauge
To Check Disc Thickness — Micrometer

TO CHECK AND RENEW BRAKE PADS

(1) Raise the front of the vehicle and place it on

chassis stands. Remove the front wheels.

(2) Inspect the brake pads on both sides of the

vehicle. If the friction material on one or more of the
pads is less than 2 mm thick or contaminated with
fluid or grease, renew the brake pads as a set as
follows.

NOTE: If the brake pads are contaminated,
trace and rectify the cause prior to installing
the new set of pads.

(3) Drain approximately two thirds of the brake

fluid from the master cylinder reservoir. This can be
done by loosening the bleeder valve on the caliper and
allowing the fluid to drain into a container. Discard
this fluid.

Brakes

179

Installed view of the front brake pads, spring clips and

shims.

NOTE: Do not drain all the fluid from the
reservoir or it will be necessary to bleed the
hydraulic system. The fluid is drained from
the reservoir to prevent overflow when the
caliper piston is pushed back into the caliper
bore to facilitate pad renewal.

(4) Remove the lower guide bolt and rotate the

caliper body upwards, pivoting on the upper guide
bolt.

(5) Remove the brake pad assemblies from the

anchor plate.

(6) Noting the installed positions, remove the

spring clips from the anchor plate and the shims from
the brake pads.

(7) Squarely push the piston into its bore in the

caliper body. If necessary, use a G clamp to push the
piston into the caliper body. Check for fluid leaks
from the caliper body.

(8)

If necessary, check the disc runout and

thickness as described under the Brake Disc heading.

(9) Ensure that the guide bolts move freely in the

anchor plate and that the dust boots are in good
condition.

(10) Install the brake pads, shims and spring

clips
in the position noted on removal.

(11) Rotate the caliper body downwards, to re-

turn to its original position. Lubricate the lower guide
bolt with suitable grease. Install and tighten the guide
bolt to the specified torque.

(12) Repeat the procedure on the opposite front

brake assembly.

(13) Replenish the master cylinder reservoir with

the recommended fluid to the correct level and pump
the brake pedal several times to locate the disc pads.

(14) Install the front wheels and lower the

vehicle
to the ground.

(15) Road lest the vehicle and check for correct

brake operation.

CALIPER

To Remove and Install

(1) Raise the front of the vehicle and place it on

chassis stands. Remove the relevant front wheel.

(2) Remove the brake hose retaining bolt and

plug the hose to prevent the loss of fluid and the
ingress of dirt.

(3) Remove the bolts retaining the caliper an-

chor plate to the steering knuckle and slide the caliper
off the disc.

Installed view of the front brake caliper.

Installation is a reversal of the removal procedure

with attention to the following points:

(1) Tighten the caliper anchor plate bolts to the

specified torque.

(2) Install the brake hose to the caliper

body
ensuring that new seal washers are installed.

NOTE: Ensure that the brake hose is cor-
rectly located against the protrusion on the
caliper body.

(3) Bleed the brake hydraulic system as de-

scribed under the Hydraulic System heading.

(4) Install the front wheel and lower the vehicle

to the ground.

(5) Road test the vehicle and check for correct

brake operation.

To Dismantle

(1) Raise the front of the vehicle and place it on

chassis stands. Remove the relevant front wheel.

(2) Remove the brake hose retaining bolt from

180

Brakes

the caliper body. Plug the brake hose to prevent the
loss of fluid and the ingress of dirt. Remove and
discard the sealing washers.

(3) Remove the guide bolts and slide the caliper

body from the anchor plate and pad assembly.

(4) Remove the piston dust cover retaining clip.

Remove and discard the dust cover.

B R A K E P A D

BRAKE PAD

Dismantled view of the front brake caliper.

(5) Place a piece of wood in front of the piston

and using low air pressure applied to the brake hose
aperture, gently force the piston from the caliper bore.

(6) Using a thin blunt probe, preferably made

from wood or plastic, remove and discard the piston
seal from the groove in the caliper bore.

(7) Clean all the caliper components in methyl-

ated spirits and arrange the components in order, on
a clean, dry surface to aid in assembly.

To Inspect

(1) Inspect the caliper bore and piston for pit-

ting, wear or damage. Renew the caliper assembly or
piston if damage is evident.

NOTE: Slight rust spots in the caliper bore
may he removed with fine emery paper. The
piston must not be polished as the plated
surface wilt be damaged.

(2) Inspect the guide bolts for wear or damage.

Renew as necessary.

To Assemble

(1) Dip a new piston seal in clean hydraulic

brake fluid. Insert the seal into the groove in the
caliper bore ensuring that the seal is correctly seated
and not twisted.

(2) Install a new dust cover to the piston prior to

installing the piston to the caliper bore.

(3) Coat the piston and caliper bore with clean

hydraulic brake fluid and insert the piston squarely
into the caliper bore.

(4) Locate the dust seal in the groove of the

caliper body and install the retaining clip.

(5) Lubricate the guide bolts using a suitable

grease. Install the caliper body to the anchor plate and
install and tighten the guide bolts to the
specified
torque.

(6) Replenish the master cylinder reservoir with

the recommended fluid and bleed the brakes as
described under the Hydraulic System heading.

(7) Install the front wheels and lower the vehicle

to the ground.

(8) Road test the vehicle and check for correct

brake operation.

BRAKE DISC

To Check Runout

(1) Raise the front of the vehicle and support it

on chassis stands. Remove the relevant front wheel.

(2) Install the wheel nuts with the flat side of

the
wheel nut towards the disc. Lightly tighten the nuts to
secure the disc against the hub.

Rotate the hub and check for disc runout.

(3) Mount a dial gauge stand to a suspension

component and position the dial gauge plunger
against the wheel hub. Check that the end float is less
than 0.05 mm. Excessive end float will necessitate
renewal of the hub bearing.

(4) Position the dial gauge plunger against the

centre of the brake disc. Rotate the hub and measure
the runout. Maximum allowable runout is 0.07 mm.

(5) If the runout exceeds Specifications, machine

or renew the brake disc.

(6) Install the front wheel and lower the vehicle

to the ground.

To Remove and Install

(1) Raise the front of the vehicle and support it

on chassis stands. Remove the relevant wheel.

(2) Remove the bolts retaining the caliper an-