Technician A says vacuum for most power brake systems is supplied by the engine intake manifold. Technician B says many late-model cars that use intake manifold vacuum as the power source for the power brakes have a vacuum reservoir. Who is correct?
A)A only
B)B only
C)Both A and B
D)Neither A nor B

Question

Quizplus · Accepted Answer

Both technicians are correct. In most power brake systems, vacuum is supplied by the engine intake manifold. However, many late-model cars that use this as the power source for the power brakes have a vacuum reservoir to ensure consistent vacuum supply even during times when the engine is not producing enough vacuum, such as during hard acceleration or when the engine is idling.

Technician a Says Vacuum for Most Power Brake Systems Is