Brake Master Cylinder: Service and Repair

WARNING
This procedure is for cars without antilock brake system. If you have a car with antilock brakes, see Antilock Brake System, Master Cylinder. Service and Repair

REMOVAL

Exploded View Of Master Cylinder:

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.
^ In the case of brake fluid leakage from the master cylinder, disassemble the cylinder. Then check piston cups for deformation or scratches and replace necessary parts.

1. Connect a vinyl tube to air bleeder valve and the other end to a suitable container.
2. Drain brake fluid from each air bleeder valve, depressing brake pedal to empty fluid from master cylinder.
3. Remove brake line flare nuts.
4. Remove master cylinder mounting nuts.

DISASSEMBLY

Bending Stopper Claws:

1. Bend claws of stopper cap outward.

Removing Valve Stopper:

2. Remove piston assemblies. If it is difficult to remove secondary piston assembly, gradually apply compressed air through fluid outlet.
3. Remove reservoir tank.

INSPECTION
Check master cylinder inner wall for pin holes or scratches. Replace if damaged.

ASSEMBLY

Positioning Piston Cups. Less ABS:

1. Insert secondary piston assembly. Then insert primary piston assembly.
^ Pay attention to direction of piston cups in figure shown. Also, insert pistons squarely to avoid scratches on cylinder bore.

Installation Of Stopper Cap:

2. Before installing stopper cap, ensure that claws are bent inward and install stopper cap.
3. Push reservoir tank seals into cylinder body.
4. Push reservoir tank into cylinder body.

INSTALLATION AND BLEEDING





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 "DOT 3" brake fluid and never reuse drained 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 the rest of the system. Service and Repair