Air Brakes 1-20

The application pressure gauge shows how much air pressure you:

• Have in the air tanks.

• Have in a modulating control valve.

• Are applying to the brakes

The spring barkes used on the chambers in a straight truck will bring you to a stop when air pressure drops below ___ psi

• 60

• 100

• 20

Some air brake system have an alcohol evaporator. What may happen if you don't keep the proper level alcohol?

• The S-cam may not take back when you release the brake pedal.

• Ice may form on the brake drums and wear them out.

• Ice may form in the air brake valves and cause brake failure

The safety valve is set automatically when pressure is:

• 50

• 150

• 100

Why drain water from compressed air tanks?

• Water cools the compressor to much.

• Water can freeze in cold weather and cause brake failure.

• Water low boiling point reduces braking power.

Your truck or bus has a dual air brake system. if a low-pressure warning come on for only one system, what should you do?

• Reduce your speed and test the remaining system while under way.

• Reduce your speed and rive to the nearest garage for repairs

• Bring your vehicle to a complete stop right away and safely park. Continue only afte the system is fixed

Your Truck has a dual air system and one of the systems loses its pressure. What will happen?

• Either the front or back brake will not be fully operational

• Brake drums will not be fully pressurized

• The manual slack adjusters of the S-cam brakes will not be set properly

Parking or emergency brakes of trucks and buses can be legally held on by ___ pressure.

• Air

• Fluid

• Spring

If your truck or bus has dual parking control valves, you can use pressure from a separate tank to:

• Balance the service brake system when you are parked.

• Release the spring emergency/parking brakes to o move a short distance

• Stay parked twice as long without using up service air pressire.

If your truck has a properly functioning dual air brake system and minimum size air tanks, the air pressure should build up from 85 to 100 psi within how many seconds?

• 30

• 45

• 60