REMOVAL & INSTALLATION
See Figures 1, 2, 3, 4 and 5
- Disconnect the negative battery cable. Working inside the vehicle below the instrument panel, disconnect the booster valve operating rod from the brake pedal assembly.
- Disconnect the wires from the stoplight switch.
- Disconnect the manifold vacuum hose from the booster unit.
- Unbolt and remove the master cylinder from the booster, without disconnecting the brake lines. Support the master cylinder out of the way.
- Remove the four bracket-to-dash panel attaching bolts.
- Remove the booster and bracket assembly from the dash panel, sliding the valve operating rod out from the engine side of the dash panel.
- Mount the booster and bracket assembly to the dash panel by sliding the valve operating rod in through the hole in the dash panel, and installing the attaching bolts.
- Connect the manifold vacuum hose to the booster.
- Install the master cylinder.
- Connect the stop light switch wires.
- Working inside the vehicle below the instrument panel, install the rubber boot on the valve operating rod at the passenger side of the dash panel.
- Connect the valve operating rod to the brake pedal with the bushings, eccentric shoulder bolt, and nut.
- Reconnect the negative battery cable. Check operation of stop-lights and brake system.
BRAKE BOOSTER PUSHROD ADJUSTMENT
The pushrod has an adjustment screw to maintain the correct relationship between the booster control valve plunger and the master cylinder piston. If the plunger is too long it will prevent the master cylinder piston from completely releasing hydraulic pressure, causing the brakes to drag. If the plunger is too short it will cause excessive pedal travel and an undesirable clunk in the booster area. Remove the master cylinder for access to the booster pushrod. Adjust to the following specifications:
To check the alignment of the screw, fabricate a gauge (from cardboard, following the dimensions in the above illustration) and place it against the master cylinder mounting surface of the booster body. Adjust the pushrod screw by turning it until the end of the screw just touches the inner edge of the slot in the gauge. Install the master cylinder and bleed the system.