Amigo 4WD L4-2.3L (4ZD1) (1989)
Vacuum Brake Booster: Description and Operation
Single Vacuum Unit
In a normal operating mode, with the service brakes in the released position, the single vacuum booster operates with vacuum on one side of the
diaphragm. When the brakes are applied, air at atmospheric pressure is admitted to one side of the diaphragm to provide the power assist. When the
service brake is released, the atmospheric pressure is cut off from the one side of the diaphragm. The air is then drawn from the booster through the
vacuum check valve to the vacuum source.