1987 MAZDA 626 sensor

1 1 MASTER CYLINDER
MASTER CYLINDER
REMOVAL
Remove in the sequence shown in the figure, referring to removal note for specially marked parts.
Caution
Brake fluid will damage painted surfaces. If it does get on a painted surface, wipe it off
immediately.
1. Fluid level sensor connector
2. Brake pipe
76G11X-011
3. Master cylinder
4. Clutch pipe holder (LHD MTX ABS)
Removal Note
Brake pipe (Flare nut type)
1. Place rags under the master cylinder to prevent
brake fluid from dripping on painted surfaces.
2. Disconnect the brake pipe from the master cylin-
der with the SST.
76G11X-012
11—14

MASTER CYLINDER 1 1
DISASSEMBLY AND ASSEMBLY (EXCEPT RHD DOHC TURBO)
1. Pour out the brake fluid.
2. Disassemble in the sequence shown in the figure, referring to disassembly note for specially marked
parts.
3. Assemble in the reverse order of disassembly, referring to assembly note for specially marked parts.
Caution a) Do not to allow any foreign material into the master cylinder during repairs. b)Do not scratch the inside of the cylinder or the outer surface of the piston.
Note
The primary piston assembly is not repairable. Replace it as an assembly.
76G11X-013
1. Fluid level sensor 5. Secondary piston assembly
2. Stopper screw and O-ring 6. Reservoir assembly
3. Snap ring 7. Bushing
4. Primary piston assembly
11—15

1 1 MASTER CYLINDER
DISASSEMBLY AND ASSEMBLY (RHD DOHC TURBO)
1. Pour out the brake fluid.
2. Disassemble in the sequence shown in the figure, referring to disassembly note for specially marked
parts.
3. Assemble in the reverse order of disassembly, referring to assembly note for specially marked parts.
Caution a) Do not to allow any foreign material into the master cylinder during repairs. b)Do not scratch the inside of the cylinder or the outer surface of the piston.
Note
The primary piston assembly is not repairable. Replace it as an assembly.
76G11X-014
1. Stopper screw and O-ring
2. Snap ring
3. Spacer
4. Piston guide assembly
5. Primary piston assembly
6. Stopper
7. O-ring
8. Piston guide cup
9. Piston guide
10. Secondary piston assembly
11. Stopper
12. Piston cup
13. Washer
14. Secondary piston
15. Spring
16. O-ring
17. Screw
18. Bushing
19. Reservoir assembly
20. Fluid level sensor
21. Master cylinder body
11—18

POWER BRAKE UNIT 1 1
76G11X-034
INSPECTION OF CHECK VALVE
Note (MTX)
The check valve is pressed into the vacuum
hose. There is an arrow on the hose surface
to indicate direction of installation.
Inspection
1. Disconnect the vacuum hose from the engine.
2. Apply suction and pressure to the hose from the
engine side. Check that air flows only toward the
engine.
If the air passes in both directions or not at all, re-
place the check valve (along with the hose).
REMOVAL
Remove in the sequence shown in the figure, referring to removal note for specially marked parts.
1. Fluid level sensor connector
2. Vacuum switch coupler
(RF, RF-CX)
3. Brake pipe
4. Master cylinder
5. Clutch pipe holder
6. Vacuum hose and check
valve
7. Clevis pin
8. Steering shaft
76G11X-069
9. Power brake unit
10. Gasket
11. Locknut
12. Operating lever
11-29

ANTI-LOCK BRAKE SYSTEM (ABS) 1 1
ANTI-LOCK BRAKE SYSTEM (ABS)
STRUCTURAL VIEW
1. Hydraulic unit 4. Sensor rotor (front) 7. Wheel speed sensor (rear)
2. Relay box 5. Wheel speed sensor (front) 8. Sensor rotor (rear)
3. Control unit 6. Check connector
11—71

1 1 ANTI-LOCK BRAKE SYSTEM (ABS)
Troubleshooting Main Flow Chart
Check that the ABS warning light operates.

• Turn ignition switch OFF
to
ON, and check that ABS warning light illuminates constantly.

Flashing (Past failure)
OK
Check the ABS for failure.
• Start engine, and observe flashing
of
warning light.
Does not
illuminate
constantly
Warning light Possible cause
Does
not il-

luminate
at all

Refer
to
page 11—86.

ON
Alternator
L
ter-minal output Wiring harness (ALT-control unit) Control unit

OFF
1 sec

Alternator
L
ter-minal output Wiring harness (ALT-control unit) Control unit

ON
Relay box wiring harness (warning light-control unit) Control unit

OFF
1 sec

Relay box wiring harness (warning light-control unit) Control unit

No illumination
(Not diagnosed)
Illuminates constantly
(Present failure)
ABS is usually operating cor-rectly.
Consult table below when ABS failure
is
still suspected.
System Possible cause
ABS Brake light switch
Both rear wheel speed sensors
Control unit Proportioning
valve
in hy-
draulic unit
Other than Refer
to

ABS troubleshoot-ing guide
on

page 11—5.

Repair failures with flow
chart. (Refer to page
11—76.)
76G11X-054
11-74

ANTI-LOCK BRAKE SYSTEM (ABS) 1 1
Diagnosis Table
Note
Flashing of the warning light shows past failure, and its illumination shows present failure.
Diagnosis indication Possible failure Flow chart
No. Warning light Voltmeter Possible failure Flow chart
No.
ON
n
i2vn
OV

Hydraulic unit Harness
Right front wheel speed
sensor ABS-1
ON
n nn
Hydraulic unit Harness Left front wheel speed sensor ABS-2

OFF

Hydraulic unit Harness Left front wheel speed sensor ABS-2

OFF
nnn

Hydraulic unit Harness
Rear wheel speed sensor ABS-3

n
nnnn
Right front sensor rotor ABS-4

n
nnnnn
Left front sensor rotor ABS-5

JLilTUITLTL
Right rear sensor rotor ABS-6

jirLruiJum
Left rear sensor rotor ABS-7

J n
Hydraulic unit Harness
Control unit connector (11-pin)
ABS-8

nnnn

Hydraulic unit Harness
Control unit connector (11-pin)
ABS-8

J nn

Relay box
Hydraulic unit
Harness
ABS-9

jumruiTL

Relay box
Hydraulic unit
Harness
ABS-10

j nnn
Relay box
Hydraulic unit
Harness
ABS-11

jinnjuuL

Relay box
Hydraulic unit
Harness ABS-12

j nnnn

Relay box
Hydraulic unit
Harness
ABS-13

jiruuirirL

Relay box
Hydraulic unit
Harness
ABS-14

j nnnnn
Hydraulic unit Harness Control unit
ABS-15

juuuiruL

Hydraulic unit Harness Control unit ABS-16

j JinjiruifL.
Control unit
ABS-17

jiruinjiri—
JinjiruifL.
Control unit
ABS-18

j
No signal; failure condi-tions not stored
in
memory
Control unit Control unit connector (17-pin) Battery capacity Alternator output voltage Wiring harness (warning light-control unit-check connector)
Inspect, and repair or replace as necessary
j
No signal; failure condi-tions not stored
in
memory
No problem When warning light does
not
illuminate with engine running and
no
jumper wire

76G11X092
11-75

1 1 ANTI-LOCK BRAKE SYSTEM (ABS)
Flow Chart (Refer to Wiring Diagram, Page 11—72.)
ABS-1
Possible failure
Right front wheel speed sensor, Harness, Hydraulic unit
Disconnect Q-01 (11-pin) connec-tor. Check continuity
at
harness side.
Q-01 (11-pin)
I
Continuity
Y (2C) Ground No

OK

Measure resistance
at
harness side.
Q-01 (11-pin) Resistance
Y (2C)
i 0
(2D) 800—1200
Q
OK
NG
Repair harness.

(Control unit — Right front sensor)
NG

Disconnect Q-03. Measure resistance
at
sensor.
Q-03 Resistance
Y
[ O
800—1200 Q

NG
Replace right front wheel speed sensor.

OK
Repair harness.

(Control unit — Right front sensor)

Check followings*
• Clearance between sensor and rotor standard: 0.3—1.1
mm
(0.012-0.043
in)
• Objects sticking
to
sensor
or
rotor
• Damaged sensor
or
rotor
• Sensor installation Tightening torque: 16-23 N-m (1.6-2.3 m-kg, 12—17 ft-lb)

OK

Connect Q-01 (11-pin) connector. Jump GB
to B at
Q-07 connector. Start engine. Check that warning light stays ON. Drive vehicle and check that warning light flashes (0.25 sec ON OFF)
at 15
km/h
(9
mph).

NG
Repair
or
replace
as
necessary
* All conditions can
be
verified
as
follows,
if an AC
voltmeter
is
available. 1. Jack
up
vehicle. 2. Measure sensor voltage while rotating right front wheel
one
revolution
per
second.
Q-01 (11-Din) Voltage (AC)
Y (2C) O (2D) More than 0.25V

NG
Check Q-01 connector,
or
Replace control unit.

OK

Replace hydraulic unit.

76G11X-055
11—76