Brake Master Cylinder: Service and Repair

REMOVAL

CAUTION: Be careful not to splash brake fluid on painted areas; it may cause paint damage. If brake fluid is splashed on painted areas, wash it away with water immediately.

1. Connect a vinyl tube to air bleeder valve.
2. Drain brake fluid from each air bleeder valve, depressing brake pedal to empty fluid from master cylinder.
3. Remove brake pipe flare nuts.
4. Remove master cylinder mounting nuts.

DISASSEMBLY





1. Bend claws of stopper cap outward.





2. Remove valve stopper while piston is pushed into cylinder.
3. Remove piston assemblies.

NOTE: If it is difficult to remove secondary piston assembly, gradually apply compressed air through fluid outlet.

4. Draw out reservoir tank.

INSPECTION
- Check for the following items. Replace any part if damaged.
Master cylinder: check for pin holes or scratches on inner wall.
Piston: check for deformation of or scratches on piston cups.

ASSEMBLY
1. Insert secondary piston assembly. Then insert primary piston assembly.





NOTE: Pay attention to alignment of secondary piston slit with valve stopper mounting hole of cylinder body.

2. Install stopper cap.





NOTE: Before installing stopper cap, ensure that claws are bent inward.

3. Push reservoir tank seals into cylinder body.
4. Push reservoir tank into cylinder body.





5. Install valve stopper while piston is pushed into cylinder.

INSTALLATION

CAUTION:
- Refill with new brake fluid "DOT 3".
- Never reuse drained brake fluid.





1. Place master cylinder onto brake booster and secure mounting nuts lightly.
2. Torque mounting nuts to 12 - 15 Nm (9 - 11 ft. lbs.).
3. Fill up reservoir tank with new brake fluid.
4. Plug all ports on master cylinder with fingers to prevent air suction while releasing brake pedal.
5. Have driver depress brake pedal slowly several times until no air comes out of master cylinder.
6. Fit brake lines to master cylinder.
7. Tighten flare nuts to: 15 - 18 Nm (11 - 13 ft. lbs.).
8. Bleed air from brake system. Refer to Brake Bleeding / Service and Repair / Bleeding Brake System.