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📖 Air Brakes Test
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1
The application pressure gauge shows how much air you:
Have in the air tanks.
Are applying to the brake ✓ CORRECT
Have in a modulating control valve.
2
The spring brakes used on the chambers in a straight truck will bring you to a stop when air pressure drops below ___ psi.
20 ✓ CORRECT
60
100
3

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

The S-cam may not take back when you release the brake pedal.
Ice may form in the air storage tank and cause a brake failure. ✓ CORRECT
Ice may form on the brake drums and wear them out.
4
Your truck or bus has a dual air brake system. If a low air pressure warning comes on for only one system, what should you do?
Bring your vehicle to a complete stop right away and safely park. Continue only after the system is fixed. ✓ CORRECT
Reduce your speed and test the remaining system while under way.
Reduce your speed and drive to the nearest garage for repairs.
5
Why drain water from compressed air tanks?
Water low boiling point reduces braking power.
Water can freeze in cold weather and cause brake failure ✓ CORRECT
Water cools the compressor too much.
6
The safety valve is set automatically when pressure is:
50
100
150 ✓ CORRECT
7
Your truck has a dual air system and one of the systems loses its pressure. What will happen?
Brake drums will not be fully pressurized.
The manual slack adjusters of the S-cam brakes will not be set properly.
Either the front or back brake will not be fully operational. ✓ CORRECT
8
Parking or emergency brakes of trucks and buses can be legally held on by ___ pressure.
Spring ✓ CORRECT
Air
Fluid
9
If your truck or bus has dual parking control valves, you can pressure from a separate tank to:
Balance the service brake system when you are parked.
Stay parked twice as long without using up service air pressure.
Release the spring emergency/parking brakes to move a short distance. ✓ CORRECT
10
If your truck or bus has dual parking control valves, you can pressure from a separate tank to:
Balance the service brake system when you are parked.
Stay parked twice as long without using up service air pressure.
Release the spring emergency/parking brakes to move a short distance. ✓ CORRECT