Vacuum Brake Booster: Service and Repair

BRAKE BOOSTER





COMPONENTS

REMOVAL
1. Remove master cylinder and gasket.





2. Disconnect vacuum hose from the booster.





3. Remove the pin and snap pin.





4. Remove the lock nut and then remove brake booster.

INSTALLATION





1. Adjust push rod length of the booster, and then install the seal on the booster assembly.
Standard length: 114.5 ± 0.5 mm (4.508 ± 0.019 inch)





2. Insert the booster and tighten the nut.
Tightening torque: 13 - 16 Nm (1.3 - 1.6 kg-m, 9.5 - 11.7 ft. lbs.)





3. Connect the booster push rod and brake pedal with a pin and install a snap pin to the pin.

CAUTION: When installing the snap pin, it mount be used new one.

4. Adjust push rod length
1) Insert the gasket onto the master cylinder.





2) Put the SST onto the gasket and tighten the adjusting bolt until the bolt touches the bottom of the wish rod hole.
3) Apply 500 mmHg vacuums with a vacuum pump.





4) Invert the SST used in step 2 and place it on the booster.





5) Check whether the clearance between the edge of the adjusting bolt and the push rod of the booster is 0 - 0.1 mm (0 - 0.004 inch)
If it is not standard clearance, loosen the lock nut of the push rod, and turn the push rod to make the adjustment.
Standard clearance: 0 - 0.1 mm (0 - 0.004 inch)
5. Install the master cylinder.
Tightening torque: 8 - 12 Nm (0.8 - 1.2 kg-m, 5.8 - 8.8 ft. lbs.)
6. Connect the vacuum hose to the brake booster.
1) Connect the vacuum hose insertion part into the brake booster tube as illustrated.





2) Insert it tightly until the fitting hexagonal end meets engine side vacuum hose, and clamp it with the hose clip.

NOTE:
^ Do not make vacuum hose twisted upon assembly.
^ Do not make air-leak at the vacuum hose connection.

7. After filling the brake reservoir with brake fluid, bleed the system.
8. Check for fluid leakage.
9. Check and adjust the brake pedal for proper operation.
10. After installing, apply grease to the contact parts of the joint pin and brake pedal.