Brake Master Cylinder: Service and Repair

REMOVAL/INSTALLATION

Fig. 3 Reservoir Connector Screw Location:

Fig. 4 Pushing Pin Until It Contacts Piston:

Fig. 5 Adjusting Piston Rod Length:

1. Clean any dirt from around reservoir cap. Remove cap, then brake fluid.
2. Remove reservoir connector screw, Fig. 3, then reservoir.
3. Disconnect brake lines from master cylinder. Do not allow brake fluid to get on painted surfaces.
4. Remove master cylinder attaching bolts, then master cylinder.
5. Adjust clearance of booster piston rod to master cylinder piston as follows:
a. Push piston rod several times to ensure reaction disc is in place.
b. Measure with gasket in place on master cylinder and booster at atmospheric pressure.
c. Set measuring tool No. 09950-98210 or equivalent, on master cylinder and push pin until it contacts piston, Fig. 4.
d. Turn tool upside down and place on booster, Fig. 5. Adjust booster piston rod length until rod end contacts piston head.
e. When adjusted as above, if negative pressure is applied to booster with engine at idle, piston to piston rod clearance should become .004-.020 inch (0.1-.5mm) for Samurai or .010-.020 (.25-.50 mm) inch for Sidekick or .004-.013 inch (.10-.35 mm) for Swift.
6. Install reservoir on master cylinder, then reservoir connector screw.
7. Install master cylinder on studs, then mounting nuts.
8. Connect hydraulic lines.
9. Fill reservoir with brake fluid.
10. Check brake pedal height and pedal travel as outlined under ADJUSTMENT PROCEDURES/BRAKE PEDAL HEIGHT and BRAKE PEDAL TRAVEL CHECK.

Overhaul

1. Remove master cylinder as outlined under
2. Remove circlip, then the primary piston.
3. Remove piston stopper bolt, then using compressed air, remove secondary piston. Blow compressed air into hole where stopper bolt was removed.
4. Reverse procedure to assemble.