Vacuum Brake Booster: Adjustments

In some cases adjustment of the brake booster pushrod is necessary to ensure proper operation of the power brake system. A pushrod that is too long will cause the master cylinder piston to close the compensating port, preventing hydraulic pressure from being released and resulting in brake drag. A pushrod that is too short will cause excessive brake pedal travel, which may cause groaning noises to come from the booster when the brakes are applied. A properly adjusted pushrod that remains assembled to the booster it was matched to during production should not require service adjustment. However, if the booster, master cylinder or pushrod are serviced, the pushrod may require adjustment.