Vacuum Brake Booster: Service and Repair

Brake Booster

REMOVAL
1) Remove or disconnect the following parts in the engine compartment.
1) Disconnect the connector of brake fluid level gauge.
2) Remove the brake pipe from the master cylinder.
3) Remove the master cylinder installation nut.

CAUTION:
In order to prevent the contact of the bracket and check valve, be sure to loosen the master cylinder mounting nut while holding the bracket with hand. Otherwise it may deform the bracket.





4) 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:
136.5 mm (5.37 in)

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





2) Mount the brake booster in position.
3) Tighten the brake booster mounting nuts.

Tightening torque:
18 Nm (1.8 kgf-m, 13.3 ft-lb)

4) Install the clevis pin and snap pin which secure the operating rod and brake pedal.





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

5) Connect the vacuum hose to the brake booster.
6) After replacing the seal sub assembly with a new part, install the master cylinder to brake booster.





CAUTION:
^ Install the bracket at the position with sufficient clearance that it does not contact with the check valve.
^ Be sure to loosen the master cylinder mounting nut while holding the bracket with hand. Otherwise the bracket may deform.





7) Connect the brake pipes to the master cylinder.

Tightening torque:
19 Nm (1.9 kgf-m, 14 ft-lb)

8) Connect the connector of the brake fluid level gauge.
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, 5.9 ft-lb)

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