Technician A says the air and vacuum valves used on a tandem diaphragm must control vacuum and atmospheric pressure on two diaphragms at the same time. Technician B says when the brakes on a tandem diaphragm system are released, there is a vacuum on both sides of each diaphragm. Who is correct?

Question

Quizplus · Accepted Answer

Both technicians are correct. Technician A is correct in stating that the air and vacuum valves must control both vacuum and atmospheric pressure simultaneously on two diaphragms in a tandem diaphragm system. Technician B is correct in stating that when the brakes are released in such a system, there is a vacuum present on both sides of each diaphragm, which is how the system returns to its default state.

Technician a Says the Air and Vacuum Valves Used on a Tandem