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-