DSL-204 Chap 34 Air Brake Circuits and Valves

Technician A says that even if an air brake system springs a small leak, the air can be replenished without a loss of braking. Technician B says that noise accompanies the movement and exhausting or air.Who is correct?

• Technician A only

• Technician B only

• Both Technician A and Technician B

• Neither Technician A nor Technician B

All of the following are advantages of air brake systems over hydraulic systems, EXCEPT:

• They enable easier and faster coupling and uncoupling of trailers from the tractor unit.

• They can maintain brake pressure at higher altitudes.

• The speed of air pressure transmission is higher.

• The supply of air is limitless.

Generally, in the case of a tractor towing a trailer, the secondary circuit supplies pressure to the __________.

• Tractor’s front axles

• Tractor’s rear brakes and trailer

• Trailer’s rear axles and tractor’s front axles

• Trailer’s front axles

What feature of air brake systems prevents a total loss of braking in the case of an air leak or component failure?

• Primary air reservoir

• Secondary brake circuit

• Air supply system

• Dual circuit system configuration

What is the commonly used color of the primary brake circuit lines?

• Blue

• Green

• Black

• Red

Compressors are __________.

• Located in the cylinder head

• Engine-driven

• Normally closed

• Like an in-line filtration system

What type of valve removes water and oil that may contaminate the supply system air?

• Drain

• Pressure protection

• Turbocharger cut-off

• Inlet pressure regulating

After entering the dryer, air passes through the desiccant before moving into the __________ reservoir.

• Purge

• Service

• Supplemental

• Air brake

Air pressure from the foot valve (signal air) is supplied to a service-control port on the __________ valve.

• Relay

• Proportioning

• Quick-release

• Service brake control

Technician A says that the stop lights are sometimes controlled by a pressure-sensitive electrical switch located at the delivery port. Technician B says the switch will close at less than 5 psi (34.5 kPa) pressure. Who is correct?

• Technician A only

• Technician B only

• Both Technician A and Technician B

• Neither Technician A nor Technician B