CDL Air Brakes Test

Air brakes use ______

• hot air

• cold air

• compressed air

• decompressed air

Air brake systems are three braking systems combined. They are _________

• emergency, service, hand

• emergency, parking, service

• parking, service, hand

• None of the above.

Which of the following pumps air into the air storage tanks?

• Safety valve

• Air compressor

• Governor

• Reservoir

The main purpose of the alcohol evaporator is to _________

• put alcohol in gas tanks

• remove alcohol from the compressor

• remove alcohol from the storage tank

• put alcohol in the air system

A safety relief valve is installed in the first tank the air compressor pumps air to.

The valve is usually set to open at what psi level?

• 130

• 140

• 150

• 160

The most common foundation brake is the _______

• wedge brake

• S-cam drum brake

• disc brake

• front brake

The brake system that applies and releases the brakes when the driver

uses the brake pedal is the __________ brake system.

• emergency

• parking

• trailer

• service

The low-air-pressure warning light must come on before

the air pressure in the tanks falls below what psi level?

• 30

• 60

• 40

• 50

Spring brakes do which of the following?

• They use air pressure to stop the vehicle

• They will not work if all the air leaks out of the air brake system

• They are held by mechanical force

• They will come on fully at 50 psi

Which of the following tells you how much pressure there is in the air tanks?

• Stop-light switch

• Application pressure gauge

• Supply pressure gauge

• Low-air-pressure warning signal