1987 MAZDA 626 Workshop Manual

MASTER CYLINDER 1 1
Stopper screw
1. Push the primary piston assembly all the way in
with a Phillips screwdriver.
2. Tighten the stopper screw.
3. Push and release the screwdriver to verify that the
position of the stopper screw is correct.
86U11X-031
INSPECTION
Check the following and replace any faulty parts.
1. Piston and cylinder bore for abnormal wear, rust,
and damage
2. Springs for weakness and damage
3. Reservoir for damage and deformation
86U11X-032
11-17

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

MASTER CYLINDER 1 1
76G11X-015
76G11X-016
76G11X-017
Disassembly Note
Stopper screw
Push the piston in by hand and remove the stopper
screw.
Snap ring
Push the piston in fully with a rod and remove the
snap ring using snap ring pliers.
Secondary piston assembly
Remove the secondary piston assembly by gradual-
ly blowing compressed air into the cylinder.
Caution
Use a rag to catch the secondary piston as-
sembly when applying compressed air.
Assembly Note
Application of brake fluid
Before assembly, apply brake fluid to the following
parts:
1. Bushing
2. Cylinder inner wall
76G11X-018
11—19

1 1 MASTER CYLINDER
3. Secondary piston cup
76G11X-019
Apply brake fluid
t Apply grease
76G11X-020
Piston guide assembly
1. Apply brake fluid to the piston guide cups; then
install them to the piston guide.
2. Install the O-rings to the piston guide.
3. Install the piston guide to the primary piston as-
sembly.
4. Apply brake fluid to the primary piston cup and ap-
ply grease to the piston guide O-rings.
5. Insert the piston guide and primary piston assem-
bly into the cylinder slowly and straight; then fit
them in the position in the cylinder.
76G11X-021
Note
If the piston guide is not easily installed in the
cylinder, use a suitable pipe and tap it to
install.
76G11X-022
11—20

MASTER CYLINDER 1 1
86U11X-031
Stopper screw
1. Push the primary piston assembly all the way in
with a Phillips screwdriver.
2. Tighten the stopper screw.
3. Push and release the screwdriver to verify that the
position of the stopper screw is correct.
INSPECTION
Check the following and replace any faulty parts.
1. Piston and cylinder bore for abnormal wear, rust,
and damage
2. Springs for weakness and damage
3. Reservoir for damage and deformation
86U11X-032
11—21

1 1 MASTER CYLINDER
INSTALLATION
1. Install in the reverse order of removal.
2. Tighten all nuts and bolts to the specified torque, referring to torque specifications.
3. After installation:
(1) Fill the reservoir with the specified fluid.
(2) Bleed air from the system. (Refer to page 11—9.)
(3) Check each part for fluid leakage.
Torque specifications
11—22

MASTER CYLINDER 1 1
Installation Note
Piston to push rod clearance adjustment
(Except RHD DOHC TURBO)
Before installing the master cylinder, check the clear-
ance between the piston of the master cylinder and
the push rod of the power brake unit as follows.
1. Place the SST on the top of the master cylinder;
then turn the adjust bolt until it contacts the bot-
tom of the push rod hole in the piston.
76G11X-024
2. Apply 500 mmHg (19.7 inHg) vacuum to the pow-
er brake unit with a vacuum pump.
76G11X-100
——x y V \ ''/v'/
\
i By Adjust bolt
86U11X-036



Locknut IV"

\ i i '
3. Invert the SST used in step 1, and place it on the
power brake unit.
4. Check the clearance between the adjust bolt and
the push rod of the power brake unit. If it is not
0 mm, loosen the push rod locknut and turn the
push rod to adjust.
76G11X-101
11-23

1 1 MASTER CYLINDER
76G11X-025

II

L
\ Clearance (B)
Clearance (A) , j Adjust nut
•I
76G11X-026
Clearance (B)
49 B043 001
Piston to push rod clearance adjustment
(RHD DOHC TURBO)
Inspection
Inspect the piston to push rod clearance in the fol-
lowing order.
1. Attach the SST to the power brake unit.
Tightening torque:
10—16 N-m (1.0—1.6 m-kg, 84—144 in-lb)
2. Apply a vacuum of 500 mmHg (19.7 inHg) us-
ing a vacuum pump.
3. Set clearance (A) between the push rod of the pow-
er brake unit and the push rod of the SST, and
clearance (B) between the adjust nut and the SST
body to 0 mm (Oin) by turning the adjust nut.
4. Remove the SST from the power brake unit keep-
ing the clearance as above. Install the SST to the
master cylinder body as shown in the figure.
5. Measure clearance (C) between the SST and the
master cylinder, and then measure clearance (B)
between the adjust nut and the SST body.
Judgement Table
Measurement Necessity of adjustment
(a) Clearance at (C) Yes
(b) Clearance at (B) Yes
Both clearances of (C) and (B) are 0 mm (Oin) No
(a) is when the push rod of the power brake unit extends.
(b) is when the push rod of the power brake unit is recessed.
76G11X-027
11-24