Brake Master Cylinder: Service and Repair

BRAKE MASTER CYLINDER SUB-ASSY
OVERHAUL
1. DRAIN BRAKE FLUID

NOTICE: Wash brake fluid off immediately if it adheres to any painted surface.

2. REMOVE AIR CLEANER ASSY
3. REMOVE BRAKE MASTER CYLINDER SUB-ASSY
a. Disconnect the level warning switch connector.





b. Using SST, disconnect the 6 brake tubes from the brake master cylinder.
SST 09023-00100





c. Remove the 2 nuts, and pull out the 2-way and brake master cylinder sub-assy.
4. REMOVE BRAKE MASTER CYLINDER RESERVOIR FILLER CAP ASSY
a. Pull out the master cylinder reservoir filler cap assy.
5. REMOVE BRAKE MASTER CYLINDER RESERVOIR STRAINER
a. Pull out the master cylinder reservoir strainer.
6. REMOVE BRAKE MASTER CYLINDER RESERVOIR SUB-ASSY
a. Remove the screw and pull out the master cylinder reservoir sub-assy.
7. REMOVE MASTER CYLINDER RESERVOIR GROMMET
a. Remove the 2 master cylinder reservoir grommets.





8. REMOVE BRAKE MASTER CYLINDER KIT (W/O VSC)
a. Place the master cylinder in the vise.
b. Remove the O-ring.
c. Push in the piston and remove the snap ring with snap ring pliers.





d. Push in the piston and remove the piston stopper bolt and gasket.
e. Remove the No. 1 piston sub-assy, pulling straight out not at an angle.

NOTICE: If pulled out at an angle, the cylinder bore could be damaged.





f. Place a shop rag and 2 wooden blocks on the work table and lightly edge until the No.2 piston sub-assy drops out of the cylinder.

HINT: Make sure the distance (A) from the rag and the top of the blocks is at least 100 mm (3.94 inch).

NOTICE: If pulled out at an angle, the cylinder bore could be damaged.





9. REMOVE BRAKE MASTER CYLINDER KIT (W/ VSC)
a. Place the master cylinder in the vise.
b. Remove the O-ring.
c. Push in the piston and remove the snap ring with snap ring pliers.





d. Push in the piston with a screwdriver, and remove the straight pin by turning the cylinder body.

HINT: Tape the screwdriver tip before use.

e. Remove the No.1 and No.2 piston sub-assy and 2 springs by hand. Pull them straight out, not at an angle.

NOTICE: If pulled out at an angle, the cylinder bore could be damaged.

10. INSPECT MASTER CYLINDER BODY
a. Check the cylinder bore for rust or scoring.





11. INSTALL BRAKE MASTER CYLINDER KIT (W/O VSC)
a. Place the master cylinder in the vise.
b. Apply lithium soap base glycol grease to new No.1 and No.2 piston sub-assy.
c. Install the No.2 and No. 1 piston sub-assy.

NOTICE:
^ If the piston is inserted at an angle, the cylinder bore could be damaged.
^ Be careful not to damage the rubber lips on the pistons.





d. Push in the piston and install a new gasket and a new piston stopper bolt.
Torque: 10 Nm (100 kgf-cm, 7 ft. lbs.)





e. Push in the piston and install the snap ring with snap ring pliers.
f. Apply lithium soap base glycol grease to a new O-ring and install the O-ring to the master cylinder.





12. INSTALL BRAKE MASTER CYLINDER KIT (W/ VSC)
a. Place the master cylinder in the vise.
b. Apply lithium soap base glycol grease to new No.1 and No.2 piston sub-assy.
c. Install the No.2 and No. 1 piston sub-assy.

NOTICE:
^ If the piston is inserted at an angle, the cylinder bore could be damaged.
^ Be careful not to damage the rubber lips on the pistons.





d. Insert the No.2 piston with the groove positioning horizontally.
e. Install the straight pin.





f. Push in the piston and install the snap ring with snap ring pliers.
g. Apply lithium soap base glycol grease to a new O-ring and install the O-ring to the master cylinder.
13. INSTALL MASTER CYLINDER RESERVOIR GROMMET
a. Apply lithium soap base glycol grease to the 2 new master cylinder reservoir grommets.
b. Install the 2 master cylinder reservoir grommets to the master cylinder reservoir sub-assy.
14. INSTALL BRAKE MASTER CYLINDER RESERVOIR SUB-ASSY
a. Install the master cylinder reservoir sub-assy to the master cylinder with the screw.
15. INSTALL BRAKE MASTER CYLINDER RESERVOIR STRAINER
a. Install the brake master cylinder reservoir strainer.
16. INSTALL BRAKE MASTER CYLINDER RESERVOIR FILLER CAP ASSY
a. Install the brake master cylinder reservoir filler cap assy.





17. INSPECT AND ADJUST BRAKE BOOSTER PUSH ROD
a. Set SST on the master cylinder and lower the pin of the SST until it slightly touches the piston.
SST 09737-00013
b. Apply chalk to the flat surfaced tip of the SST pin.
c. Turn SST upside down and measure the clearance between the brake booster push rod and SST.
Clearance: 0 mm (0 inch)

HINT:
^ If there is a clearance between the SST main body and the shell of the brake booster (floating SST main body), the push rod is protruding too far.
^ If the chalk does not stick on the tip of the brake booster push rod, the push rod protrusion is insufficient.

Adjust the clearance if either of the above conditions is detected.





d. If the clearance is outside of the specified range, fix the push rod using SST and adjust the length of the protruding adjusting bolt.
SST 09737-00020

HINT: When adjusting the push rod, depress the brake pedal sufficiently so that the push rod sticks out.





18. INSTALL BRAKE MASTER CYLINDER SUB-ASSY
a. Install the master cylinder sub-assy and 2-way with the 2 nuts.
Torque: 13 Nm (127 kgf-cm, 9 ft. lbs.)





b. Using SST, connect the 6 brake tubes to the master cylin7der sub-assy.
Torque: 15 Nm (155 kgf-cm, 11 ft. lbs.)
SST 09023-00100
c. Connect the level warning switch connector.
19. FILL RESERVOIR WITH BRAKE FLUID
20. BLEED MASTER CYLINDER
SST 09023-00100
21. BLEED BRAKE LINE
22. INSTALL AIR CLEANER ASSY
23. CHECK FLUID LEVEL IN RESERVOIR
24. CHECK BRAKE FLUID LEAKAGE