Vacuum Brake Booster: Service and Repair

Brake Booster

REMOVAL

1) Remove or disconnect the following parts in the engine compartment.
(1) Remove the brake master cylinder.
(2) Disconnect the vacuum hose from brake booster.
2) Remove the following parts from the pedal bracket.
(1) Snap pin and clevis pin
(2) Four brake booster installation nuts





3) Remove the brake booster while avoiding the brake pipe.

NOTE:
^ Make sure that the booster shell and vacuum pipe are not subject to strong impacts.
^ Be careful not to drop the brake booster. If the booster is dropped, replace it.
^ Use special care when handling the operating rod. If excessive force is applied to the operating rod, the angle may change by ±3°, and it may result in damage to power piston cylinder.
^ Be careful when placing the brake booster on floor.
^ Do not change the push rod length.

CAUTION:
^ Do not disassemble the brake booster.
^ If external force is applied from above when brake booster 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 brake booster.

Specification L:
137.6 mm (5.42 in)

If it is out of specification, adjust it with the brake booster operating rod.





2) Mount the brake booster in position.
3) Connect the operating rod to brake pedal with clevis pin and snap pin.





NOTE:
^ Replace with a new clevis pin.
^ Apply NIGTIGHT LYW NO. 2 grease to the clevis pin.

4) Connect the vacuum hose to the brake booster.
5) Mount the master cylinder onto the brake booster.
6) Connect the brake pipes to the master cylinder.
7) Connect the connector of the brake fluid level gauge.
8) Measure the clearance between the threaded end of the stop light switch and the stopper.
If it is not within the specification, adjust it by adjusting the position of the stop light switch.

CAUTION:
Be careful not to rotate the stop light switch.

Stop light switch clearance A:
0.8 mm (0.031 in)





9) Apply grease to the operating rod connecting pin to prevent it from wear.
10) Bleed air from brake system.

Tightening torque (air bleeder screw):
8 Nm (0.8 kgf-m, 5.8 ft-lb)

11) Perform a road test to make sure the brakes do not drag.