Rear brake MAZDA 626 1987 Repair Manual

OUTLINE 11
86U11X-003
1. Front disc brake
2. Hydraulic unit
3. Pipe joint
4. Master cylinder
5. Power brake unit
6. Relay box
7. Control unit
8. Wheel speed sensor
9. Sensor rotor
10. Rear disc brake
11. Parking brake lever
12. Parking brake cable
Front disc brake
(Ventilated disc)
Rear disc brake
(Solid disc)
Rear drum brake
(Leading-trailing)

1 1 OUTLINE
SPECIFICATIONS
Item Specification
Brake pedal
Type Suspended
Brake pedal Pedal lever ratio 4.2 Brake pedal
Max. stroke mm (in) LHD: 136.5 (5.37) RHD: 135 (5.31)
Master cylinder Type Tandem (with level sensor) Master cylinder
Cylinder inner diameter mm (in) 22.22 (0.87)
Front disc brake
Type Mounting support, Ventilated disc
Front disc brake
Cylinder bore mm (in) 53.97 (2.12)
Front disc brake Pad dimensions (area x thickness) mm2 x mm (in2 x in) 4,800 x 10 (7.44 x 0.39) Front disc brake
Disc plate dimensions mm (in) (outer diameter x thickness) 13 inch-wheel: 242 x 20 (9.53 x 0.79) 14 or 15 inch-wheel: 264 x 24 (10.39 x 0.94)
Rear disc brake
(Turbo model)
Type Mounting support, Solid disc
Rear disc brake
(Turbo model)
Cylinder bore mm (in) 30.2 (1.19)
Rear disc brake
(Turbo model) Pad dimensions (area x thickness) mm2 x mm (in2 x in) 2,900 x 8 (4.5 x 0.31)
Rear disc brake
(Turbo model)
Disc plate dimensions mm (in) (outer diameter x thickness) 259 x 10 (10.2 x 0.39)
Rear drum brake
(Non-Turbo model)
Type Leading-trailing
Rear drum brake
(Non-Turbo model)
Wheel cylinder inner diameter mm (in) 17.46 (0.69)
Rear drum brake
(Non-Turbo model) Lining dimensions mm (in)
(width x length x thickness) (a): 25 x 191.9 x 5 (0.98 x 7.56 x 0.20)
(b): 30 x 219.3 x 5 (1.18 x 8.63 x 0.20)
Rear drum brake
(Non-Turbo model)
Drum inner diameter mm (in) (a): 200.0 (7.87) (b): 228.6 (9.0)
Rear drum brake
(Non-Turbo model)
Shoe clearance adjustment Automatic adjuster
Power brake unit Type Vacuum multiplier Power brake unit
Diameter mm (in) 238 (9.37)
Braking force control device Type Dual proportioning valve or ABS (if equipped)
Brake fluid DOT-3 or DOT-4, or SAE J1703
Parking brake Type Center lever (Mechanical two rear brakes)
(a)...13-inch wheel in General LHD and RHD models
(b)...Except 13-inch wheel in General LHD and RHD models
11-4

BRAKE HYDRAULIC LINE 1 1
REMOVAL AND INSTALLATION OF BRAKE
LINES
1. Loosen or tighten the flare nut with the SST.
Flare nut tightening torque: 13—22 N-m
(1.3—2.2 m-kg, 9—16 ft-lb)
2. When connecting the flexible hose, do not over-
tighten or twist it.
3. After installation:
(1) Check that the hose does not contact other
parts when the vehicle bounces or when the
steering wheel is turned all the way to the right
or left.
(2) Bleed the air from the brake system. (Refer to
page 11—9.)
REPLACEMENT OF BRAKE FLUID
1. Remove the brake fluid from the reservoir with a
suction pump.
2. Fill the reservoir with new, specified brake fluid.
3. Pump out the old brake fluid by loosening the
bleeder screws (one by one) and pumping the
brake pedal. (Refer to page 11—10 for details.)
AIR BLEEDING
Air Bleeding Locations
After the following parts are removed, air bleeding is necessary after installation.
Removed part
Air bleeding location
Removed part Front Rear Removed part
Right side Left side Right side Left side
Master cylinder * * * *
Wheel cylinder or caliper
Front Right side * — — —
Wheel cylinder or caliper
Front Left side — * — —
Wheel cylinder or caliper Rear disc Right side — — * — Wheel cylinder or caliper Rear disc Left side — — — * Wheel cylinder or caliper
Rear drum Right side — — * —
Wheel cylinder or caliper
Rear drum Left side — — — *
Dual proportioning valve * * * *
Hydraulic unit (ABS) * * * *
ABS: Anti-lock Brake System 76GHX-064 *: Indicates where air bleeding is necessary
11—9

1 1 BRAKE PEDAL
Pedal-to-floor clearance
76G11X-009
REMOVAL
Remove in the sequence shown in the figure.
Pedal-to-Floor Clearance
Inspection
Check that the distance from the floor panel to the
center of the upper surface of the pedal pad is as
specified when the pedal is depressed with a force
of 589 N (60 kg, 132.3 lb).
Pedal-to-floor clearance:
LHD and RHD
95 mm (3.7 in) min.
If the distance is less than specified, check for the
following problems.
1. Air in brake system
2. Malfunction of automatic adjuster (rear drum
brakes)
3. Worn shoes or pads
86U11X-020
1. Clevis pin
2. Brake pedal
3. Return spring
4. Guide pipe
5. Bushing
6. Brake pad
11—12

1 1 POWER BRAKE UNIT
Removal Note
Steering Shaft
To remove the mounting nuts of the power brake unit,
the steering shaft must be removed. (Refer to page
10—22 for removal and installation procedures.)
76G11X-102
DISASSEMBLY AND ASSEMBLY
1. Disassemble in the sequence shown in the figure, referring to disassembly note for specially marked
parts.
2. Inspect each part, referring to inspection note.
3. Assemble in the reverse order of disassembly, referring to assembly note for specially marked parts.
8.8—13 N-m (90-130 cm-kg, 78—112 in-lb)
1. Dust boot
2. Rear shell assembly
3. Retainer
4. Bearing
5. Dust seal
6. Retainer
7. Air filters
8. Air silencer
9. Diaphragm and plate
10. Power piston assembly
11. Retainer key
12. Valve rod and plunger as-
sembly
13. Reaction disc
76G11X-070
14. Spring
15. Push rod
16. Front shell assembly
17. Retainer
18. Seal
19. Vacuum switch (RF, RF-CX)
11-30

POWER BRAKE UNIT 1 1
76G11X-071
Disassembly Note
Front and rear shells
1. Secure the front shell studs in a vise after attach-
ing suitable nuts to them to prevent damage to the
studs.
2. Before separating the front and rear shell assem-
blies, make matching marks to be used in reas-
sembly.
3. Fit a wrench onto the rear shell studs; then fasten
two of them with suitable nuts.
4. Rotate the rear shell counterclockwise to unlock.
Caution
The rear shell is spring loaded; loosen it
carefully.
Retainer key
Depress the plunger rod fully; then remove the re-
tainer key.
86U11X-049
86U11X-050
Assembly Note
Application of Grease
Before assembly, coat the parts shown in the figure
with silicon grease.
(1) Entire surface of reaction disc
(2) Dust seal lip
(3) Push rod
(4) Diaphragm-to-shell contacting surfaces
(5) Power piston
(6) Valve plunger oil seal
Retainer key
1. Push down the plunger rod.
2. Align the groove of the valve plunger with the slot
of the power piston.
3. Insert the retainer key.
86U11X-051
11—31

1 1 POWER BRAKE UNIT
Diaphragm
Install the diaphragm to the power piston and plate.
Caution
Check that the diaphragm is well seated in the
groove.
86U11X-052
Rear shell assembly
Assemble the rear shell assembly; carefully guiding
the tube end of the power piston through the dust
seal of the rear shell.
86U11X-053
Front shell and rear shells
Press down the rear shell assembly, and rotate it
clockwise until the matching marks are aligned.
Caution
Fit suitable nuts to two studs of the rear shell
and tighten them to mount the wrench.
76G11X-072
INSPECTION
1. Inspect all rubber parts. Wipe free of fluid and care-
fully inspect all rubber parts for cuts, nicks, and
other damage.
2. Check the power piston for cracks,distortion, chip-
ping, and damaged seats.
3. Inspect the reaction disc rubber for deterioration.
4. Check that the seats of the valve rod and plunger
are smooth and free of nicks and dents.
5. Inspect the front and rear shells for scratches,
scores, pits, dents, and other damage.
6. Check the diaphragm for cuts and other damage.
11—32

1
1
DUAL PROPORTIONING VALVE
B6U11X-060
DUAL PROPORTIONING VALVE
FUNCTION CHECK
1. Connect
two
pressure gauges [9,810
kPa (100

kg/cm2,1,422 psi)
]
to the brake pipes and adap-
tors
as
shown
in
the
figure.
Adaptor and flare
nut
tightening torque:
13—22 N m (1.3—2.2 m-kg, 9—16 ft-lb)
Note
Disconnect and connect the brake pipes with
the
SST
(49
0259 770B).
2. Bleed
air
from
the
brake system.
(Refer
to
page 11—9.)
76G11X-043
t 0}
^
£
»

Rear

brake
pressu
kPa
(kg/cm2,
p
>
DO

Rear

brake
pressu
kPa
(kg/cm2,
p
>
DO
TTi
A
B

Master cylinder pressure
kPa
(kg/cm2,
psi)

76G11X-044
Depress the brake pedal until the master cylinder
pressure equals A; then measure rear brake pres-
sure
A'.

Depress the brake pedal again; apply additional
pressure until
A
equals
B;
then measure pressure
B'.
If the measurements
are
not
within specification,
replace
the
valve assembly.
Install the brake pipes to the valve,
and
bleed
air

from
the
brake system.
Specification
Fluid pressure
kPa
(kg/cm2,
psi)

A A' B B'
Except General
LHD
and
RHD

1,962 (20,284)
1,962 ±
196
(20
± 2,
284
± 28)
6,867 (70,995)
3,434 ±
196
(35
± 2,
498
± 28)

General
LHD
and
RHD
2,943 (30,427)
2,943 ±
196
(30
± 2,
427
± 28)

6,867 (70,995) 4,120 ±
196
(42
± 2,
597
± 28)

11-38

1 1 FRONT DISC BRAKE
76G11X-073
86U11X066
76G11X-074
FRONT DISC BRAKE
SIMPLE INSPECTION OF DISC PAD WEAR
1. Loosen the front wheel lug nuts.
2. Jack up the front of the vehicle and support it with
safety stands.
3. Remove the wheels.
4. Look through the caliper inspection hole and check
that the remaining thickness of the pad is 2 mm
(0.08 in) min.
Note
When the remaining thickness becomes 2 mm
(0.08 in), the wear indicator informs that the
pad should be replaced by creating a squeal-
ing noise before any disc plate damage
occurs.
REPLACEMENT OF DISC PAD
Caution
Replace the left and right pads at the same
time.
1. Loosen the front wheel lug nuts.
2. Block the rear wheels firmly.
3. Jack up the front of the vehicle and support it with
safety stands.
4. Remove the wheels.
5. Remove the lower mounting bolt.
6. Pivot the caliper on the top bolt and support it.
7. Remove the V-springs.
Note
V-springs are equipped for non-asbesto pad
type.
8. Remove the pads and shims.
Warning (Asbesto pad type)
Asbestos dust is a health hazard. Do not blow
away brake dust with compressed air.
9. Apply the grease supplied in the pad attachment
set to the new shims, and attach them to the new
pads.
10. Push the piston inward with the SST and the old
pad.
11. Install the new pads and shims into the mounting
support.
12. Install the V-springs (non-asbesto pad type).
76G11X-075
11-40

REAR DISC BRAKE 1 1
REAR DISC BRAKE
SIMPLE INSPECTION OF DISC PAD WEAR
1. Loosen the rear wheel lug nuts.
2. Jack up the rear of the vehicle and support it with
safety stands.
3. Remove the wheels.
4. Look through the caliper inspection hole and check
that the remaining thickness of the pad is 1 mm
(0.04 in) min.
76G11X-082
86U11X-084
REPLACEMENT OF DISC PAD
Caution
Replace the left and right pads at the same
time.
1. Loosen the wheel lug nuts.
2. Release the parking brakes.
3. Jack up the rear of the vehicle and support it with
safety stands.
4. Remove the wheels.
5. Remove the parking brake cable from the cable
bracket and the operating lever.
6. Remove the upper mounting bolt; then pivot the
caliper.
7. Remove the V-springs.
8. Remove the pads and shims.
Warning
Asbestos dust is a health hazard. Do not blow
away brake dust with compressed air.
86U11X-085
86U11X-086
9. Apply the grease supplied in the pad attachment
set to the new shims; then attach them to the new
pads.
10. Turn the piston fully inward by rotating the SST
clockwise. Align the piston groove as shown in the
illustration.
Note
The piston groove and inner pad alignment pin
must be aligned when the inner pad is in-
stalled.
11. Install the pads and shims to the mounting support.
12. Install the pad clip.
11—47