Vacuum Brake Booster: Service and Repair

Brake Booster

REMOVAL

CAUTION:
Do not allow brake fluid to come in contact with the painted surface of the vehicle body. If it does, wash off with water and wipe away completely.

1) Disconnect the ground cable from battery and wait for at least 60 seconds before starting work.
2) Drain brake fluid from the reservoir tank completely.
3) Disconnect the air conditioner pipe.
4) Remove the power steering control module.
5) Remove the master cylinder assembly.
(1) Disconnect the fluid level gauge connector (a).
(2) Disconnect the clutch hose (b). (MT model)
(3) Disconnect the brake pipe (c).
(4) Remove the nut (d), and slowly remove the master cylinder assembly from the vacuum booster assembly.





6) Remove the clamp and remove the vacuum hose.





7) Remove the brake pipe assembly (a).
(1) Disconnect the starter connector (b) and harness clip (c).
(2) Remove the brake pipe assembly (a) from the pipe clip (d).





8) Remove the cover assembly - instrument panel LWR driver.
(1) Remove the clips, and remove the cover - instrument panel side LH.





NOTE:
Using a plastic remover, open the cover - instrument panel side LH.

(2) Remove the screws and release the clips and claws.
(3) Disconnect the harness connectors, and remove the cover assembly - instrument panel LWR driver INN and OUT.





9) Remove the nuts to remove the knee airbag module and disconnect the harness connector.





10) Remove the snap pin (a) and clevis pin (b), and remove the operating rod from the brake pedal.

CAUTION:
- Be careful not to apply excessive force to the operating rod when handling the operating rod. The angle may change by ±3°, and it may result in damage to power piston cylinder.
- Do not change the push rod length.





11) Remove the nuts, and then remove the vacuum booster assembly.

CAUTION:
- Do not disassemble the vacuum booster assembly.
- Make sure that the booster shell and vacuum pipe are not subject to strong impacts.
- Be careful not to drop the vacuum booster assembly. If the vacuum booster assembly is dropped accidentally, replace it.
- Be careful when placing the vacuum booster assembly on floor.
- If external force (a) is applied from above when the vacuum booster assembly is placed in this position, the resin portion as indicated by "P" may become damaged.








INSTALLATION

1) Check and adjust the operating rod of the vacuum booster assembly.
(1) Measure the length between the vacuum booster assembly mounting surface and clevis pin hole.
(2) If it is not within the specification, loosen the lock nut, rotate the vacuum booster assembly operating rod to adjust the rod length.

Specification L:
136.3 mm (5.37 in)





2) Install each part in the reverse order of removal.

CAUTION:
- Apply grease to the snap pin to prevent the operating rod from wear.
- Replace the clevis pin with new parts, and apply thin coat of NIGTIGHT LYW No.1 grease to the clevis pin.
- When installing the master cylinder assembly, replace the seal sub assembly with a new part, and install it to the vacuum booster assembly.





Tightening torque:
Vacuum booster assembly: 18 Nm (1.84 kgf-m, 13.3 ft-lb)
Master cylinder assembly: 13 Nm (1.33 kgf-m, 9.6 ft-lb)
Brake pipe flare nut: 19 Nm (1.94 kgf-m, 14.0 ft-lb)
Operating lock nut: 22 Nm (2.24 kgf-m, 16.2 ft-lb)
Knee airbag module: 7.5 Nm (0.76 kgf-m, 5.5 ft-lb)

3) Install the air conditioner pipe.
4) Bleed air from the brake system.
5) Perform a road test to make sure the brakes do not drag.