Nissan 47210-06P00 Booster ASY Brake

A vacuum servo unit together with a vacuum hose is considered to be an essential part of the brake hydraulic circuit with the help of vacuum generated from the intake manifold. The communication is made to the hydraulic master cylinder through the servo unit, through which the piston rod of the servo unit will act as the pushrod of the master cylinder. The design of the controls makes sure that the assistance is offered in all cases; and in releasing the brake pedal, vacuum is created in the rear chamber while all airflow passes through a small air cleaner. Ordinarily, the vacuum servo unit does not seize up and thereby require replacement unless the mileage to a car is very high. After engaging the vacuum servo unit, to check whether the unit functions properly, apply the brake pedal severally while seeing to it that the car moves the same distance as it did the first time. Specifically, when the engine is started with the pedal fully pushed down, the described pedal should have a slight downward movement. Pressing the brake pedal and shutting the engine off must see the brake pedal stay in the pressed position for about half a minute unchanged.

Disconnect the vacuum line from the servo unit.