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66 Cards in this Set

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The application pressure gauge shows how much air pressure you

Are applying to the brakes

The spring breaks used on the chamber in a straight truck will bring you to a stop one air pressure drops below ___ PSI

20

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

Ice may form in the air storage tank and cause brake failure

Your truck or bus that has 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

Why drain water from compressed air tanks

Water can freezing cold weather in cause brake failure

The safety valve a set automatically when pressure is

150 your truck has a dual air system and one of the systems loses its pressure. What will happen

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

Either the front or back break will not be fully operational

Parking or emergency brakes of trucks and buses can be legally held on by______pressure

Spring

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

Release this bring emergency parking brakes to move a short distance

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

45

How should you check that your service brakes are working properly

Park on level ground. Wait until normal air pressure is reached release a parking brake and move forward slowly at about 5 mph. Then apply the brakes firmly using the break

A straight truck or bus air brake system should not leak at the rate of more than ______PSI per minute with the engine off and the brakes released

2

During normal driving spring breaks are usually held back by

Air pressure

The air compressor stops pumping air at what PSI

125

The driver must be able to see a low air pressure warning which comes on before pressure in the service air tanks fall below____ PSI

60

Excessive use of the service breaks result in overheating which can lead to

Expansion of the brake drums

The most common type of foundation break found on the heavy vehicles is the

S – cam drum

If you must make an emergency stop you should break so you

Can steer and so your vehicle stays in a straight line

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

Stop right away and safely park. Continue only after the system is fixed

If your vehicle has an alcohol evaporator every day during cold weather you should

Check and fill the alcohol level

The air loss rate for a straight truck or bus with the engine off in the brakes on should not be more than

Three PSI in one minute

The driver must be able to see a low pressure warning which comes on for pressure in the service air tanks fall below____psi

60

The breaking power of the spring breaks

Depends on the service breaks being in adjustment

The airbrake lag distance at 55 mph on dry pavement adds about_____feet

32 feet

Total stopping distance for airbrakes is longer than that for hydraulic breaks due to ____distance

Breaking lag

It is excepted that too much heat caused by using your brakes too often could also cause

Break to fade or fail

Repeatedly partially releasing impressing the brake pedal may result in

A loss of break air pressure

The brake system that applies and releases the Brakes when the driver uses the brake pedal is the________ break system

Service

A slacking adjusters free play needs to be adjusted if it's more than about_____.. how many inches when you pull hard on it

1inch

And air brake system is fully charged at what PSI

125

Your truck or bus has dual air brake system. If a low pressure warning comes on for only one system what should you do

Bring the vehicle to a safe stop and safely Park continue only after the system is fixed

The brake pedal and an air brake system

Controls the air pressure applied to put on the brakes

The S-cam

Forces the brake shoes against the inside of the brake drum

Under normal conditions in order to engage the parking brake driver

Let the air out of the air brake system

All airbrake equipped vehicles have

A supply pressure gauge

With airbrake vehicles the parking brake should be used

Whenever you leave the vehicle unattended

A straight truck or bus airbrake system should not leak at the rate of more than ____PSI per minute with the engine off and the brakes released

2

Which of these is not a proper time to apply the parking brake

To break the vehicle very hard and other word when coming down the steep grade

With airbrakes vehicles the parking brake should be used

Anytime when the vehicle is parked

Why should you drain the water from the compressed air tanks

Water can freezing cold weather and cause brake failure

If the spring breaks are on when should you push the brake pedal

Never

To check the free play of manual slack adjusters of s-cam breaks you should park on

Level ground check the wheels and release the parking break

Excessive heat caused by using your brakes too often could also cause

Breaks to fade or fail

The use of brakes on a long and Steep Downgrade under normal conditions it's only a supplement to

The breaking effect of the engine

The most important thing to do when a low air pressure warning comes on is

Stop and safely parked as soon as possible

The parking or emergency brake on a heavy vehicle can only be held in position by something that cannot leak away like

Sring pressure

Air breaking takes more time than hydraulic breaking because air

Takes more time to flow through the lines than hydraulic fluid

When brakes are applied the brakes shoes will Press against the

Brake drum or disc

The safety valve discharges automatically at pressure of

150

Emergency stap breaking is

Press on the brake pedal as hard as you can release the brakes when the wheels locked put on the brakes again when the wheels start rolling

If the air pressure is not built up with in the correct amount of time then

Your air pressure may drop to a low point while driving requiring emergency stop

Safety valve reduce pressure at ______PSI

150

The supply pressure gauge shows how much pressure

Is in the air tanks

The breaking power of the spring breaks

Depends on the service breaks being in adjustment

Your brakes are fading when

You have to push harder on the brake pedal to control your speed on a downgrade

The air compressor governor controls

When air is pumped into the air tanks

Modern air brake systems combine three different systems they are The service,


The parking and the_____ brakes

Emergency

If you do not have automatic tank drains how often should you drain the oil and water for the bottom of the compressed air storage tanks

At the end of each day of driving

The proper use of the brakes when going down the long steep grade after selecting a proper gear is to break until your speed is about_______\ miles per hour below the posted speed for your safety and release your breaks

5 mph

An ideal conditions a truck or bus with an air brake going at 55 mph would require stopping distance of how many feet

More than 300 feet

When is it OK to leave your truck unattended without applying the parking brakes and choking the wheel

Never

The stop light switch

Turns on your brake lights to Warn drivers behind you

It is not safe to drive a vehicle that has brake drums with cracks in there longer than_____ of the width of the friction area

1/2

To test air service breaks you should

Break firmly while slowly moving forward

If you're driving down to the steep downgrade and you have rates of speed of 40 Miles per hour. You would apply the service break until your speed drop to below____ miles per hour

35

To check slack adjusters on S Cam brakes

Park on level ground and chock the wheels to prevent the vehicle from moving release the parking break so you can move the slack adjusters