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66 Cards in this Set
- Front
- Back
The application pressure gauge shows how much air pressure you |
Are applying to the brakes |
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The spring breaks used on the chamber in a straight truck will bring you to a stop one air pressure drops below ___ PSI |
20 |
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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 |
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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 |
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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 |
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Parking or emergency brakes of trucks and buses can be legally held on by______pressure |
Spring |
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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 |
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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 |
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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 |
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The most common type of foundation break found on the heavy vehicles is the |
S – cam drum |
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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 |
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Repeatedly partially releasing impressing the brake pedal may result in |
A loss of break air pressure |
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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 |
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Under normal conditions in order to engage the parking brake driver |
Let the air out of the air brake system |
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All airbrake equipped vehicles have |
A supply pressure gauge |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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Modern air brake systems combine three different systems they are The service, The parking and the_____ brakes |
Emergency |
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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 |
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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 |
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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 |
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When is it OK to leave your truck unattended without applying the parking brakes and choking the wheel |
Never |
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The stop light switch |
Turns on your brake lights to Warn drivers behind you |
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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 |
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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 |
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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 |