Vacuum Brake Booster: Service and Repair

POWER BRAKE BOOSTER

REMOVAL
1. Remove the remote ground cable from the ground stud located on the left shock tower.





2. Correctly isolate remote ground cable by installing the ground cable insulator on the strut tower ground stud as shown (Fig. 49). This will prevent accidental grounding of the remote ground cable.
3. Disconnect the wiring harness connector and vacuum hose at speed control servo.
4. Remove speed control servo mounting nuts. Leaving cable attached, move servo out off to the side.
5. Remove the master cylinder from the booster.
6. Remove the vacuum hoses from the check valve located on the power brake vacuum booster.





7. Remove the electrical connector and mounting screw from the purge solenoid mounted on the left frame rail (Fig. 50). Allow the solenoid to drop downward.





8. Locate the power brake vacuum booster input rod to brake pedal attachment under instrument panel. Position a small screwdriver between the center tang on the power brake booster input rod to brake pedal pin retaining clip (Fig. 51).
Rotate screwdriver enough to allow retaining clip center tang to pass over end of brake pedal pin. Then pull retaining clip off brake pedal pin. Discard retaining clip. Replace only with a new retaining clip when assembled.





9. Remove the 4 nuts attaching power brake vacuum booster to dash panel. Nuts are accessible from under dash panel in area of the steering column and pedal bracket assembly (Fig. 52).
10. Slide power brake vacuum booster straight forward until mounting studs clear dash panel, and remove from vehicle.

CAUTION: Do not attempt to disassemble the power brake vacuum booster it is to be serviced ONLY as a complete assembly.

INSTALLATION
1. Position power brake booster onto dash panel.
2. Install and torque the 4 power brake vacuum booster mounting nuts (Fig. 52) to 29 Nm (250 inch lbs.) torque.
3. Using lubricate, or an equivalent, coat the surfaces of the brake pedal pin that contact the power brake vacuum booster input rod.
4. Connect power brake vacuum booster input rod to brake pedal pin and install a NEW retaining clip. Use only a new retainer clip DO NOT USE the old clip.
5. Install the purge solenoid to the left frame rail and connect its wiring harness (Fig. 50).
6. Install the vacuum hoses on the booster check valve.
7. Install the master cylinder and connect the fluid level switch.
8. If equipped, install speed control servo on the mounting studs. Install the 2 speed control servo bracket mounting nuts and tighten to a torque of 6 Nm (55 inch lbs.). Install electrical connector and vacuum hose on speed control servo.
9. Install the throttle cable, and if equipped, the speed control cable on the cam of the throttle body assembly.
10. Install the remote ground cable on the ground stud located on the left strut tower. Install and securely tighten the ground cable attaching nut.
11. Check brake lamp operation. If required, adjust brake lamp switch as necessary.
12. Road test vehicle to ensure proper operation of the vehicles brake system and speed control.