Amigo 4WD L4-2.3L (4ZD1) (1989)
Vacuum Brake Booster: Description and Operation
Tandem Vacuum Unit
In a normal operating mode, with the service brakes in the released position, a tandem vacuum booster operates with vacuum on both sides of its
diaphragms. When the brakes are applied, air at atmospheric pressure is admitted to one side of each diaphragm to provide the power assist.