Vacuum Brake Booster: Service and Repair

REMOVAL






1. Remove the primary and secondary brake tubes from master cylinder.
2. Remove 2 nuts attaching the master cylinder
3. Carefully slide the master cylinder off the mounting studs on vacuum power brake booster.






4. Disconnect the vacuum supply hose from the intake manifold at the vacuum booster check valve. DO NOT REMOVE THE CHECK VALVE FROM THE POWER BRAKE BOOSTER.






5. From under instrument panel, position a small screwdriver between the center tang on the power brake booster input rod to brake pedal pin retaining clip.
6. Rotate screwdriver enough to allow retainer clip center tang to pass over end of brake pedal pin and pull retainer clip off pin. Discard retainer clip. It is not to be reused, replace only with a new retainer clip.






7. Remove the four nuts that attach the vacuum booster to the vehicle dash panel. Nuts are accessible from under the dash panel in the area of the steering column and pedal bracket.
8. Slide the vacuum booster up and forward until the mounting studs on the back of the vacuum booster are past dash panel, then remove the vacuum booster from the vehicle.

CAUTION: Do not attempt to disassemble power brake unit as this booster is serviced ONLY as a complete assembly.

INSTALLATION

NOTE: When installing vacuum power brake booster, be sure gasket is between vacuum booster and dash panel.

1. Align mounting studs on back of vacuum power brake booster with the holes in dash panel and install the vacuum booster firmly against the cowl panel.
2. Install and tighten the 4 nuts mounting the vacuum booster to the dash panel to a torque of 29 Nm (250 inch lbs.).
3. Using lubricate, or an equivalent, coat the bearing surface of the brake pedal pin.
4. Connect power brake booster input rod to brake pedal pin and install a NEW retainer clip. Use only a new retainer clip. DO NOT USE the old clip.
5. Check stop light operation.
6. Connect the vacuum hose from the intake manifold onto the check valve located on the vacuum booster.
7. Position master cylinder over studs on power brake unit and align push rod with master cylinder piston.
8. Push master cylinder against front of power brake booster.
9. Install the master cylinder to power brake unit mounting nuts and tighten to 28 Nm (250 inch lbs.) torque.
10. Bleed the master cylinder assembly prior to connecting the primary to secondary brake tubes. See Master Cylinder, Brakes, Service and Repair, Service Procedures, Master Cylinder Bleeding for the proper procedure.
11. Connect brake tubes to master cylinder primary and secondary ports. Tighten the brake tube nuts to a torque of 17 Nm (145 inch lbs.) torque.