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11 Cards in this Set
- Front
- Back
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If your truck or bus has dual parking control valves, you can use pressure from a separate tank to:
A. release the spring emergency/parking brakes to move a short distance B. Apply more brake pressure if the main tank is getting low C. Balance the service brake system whenever you are parked |
During normal driving, spring brakes are usually held back by
A. Bolts B. Air pressure C. Spring pressure |
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The most common type of foundation brake found on heavy vehicles is the:
A. Wedge drum B. S-cam drum C. Disc brake |
The parking or emergency brakes of trucks and buses can be legally held on by _______ pressure
A. Spring B. Fluid C. Air |
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The air compressor governor controls:
A. When air is pumped into the air storage tanks B. The speed of the air compressor C. Air pressure applied to the brakes |
A supply pressure gauge tells you how much pressure is in the:
A. air tanks B. tractor brake lines C. trailer brake lines |
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When you apply the brakes, the brake shoes/linings are pressed against the
A. brake drum B. Slack adjuster C. S-cam |
Why drain water from compressed air tanks?
A. The low boiling point of water reduces braking power B. Water can freeze in cold weather and cause brake failure C. To keep from fouling the air compressor oil |
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Some air brake systems have an alcohol evaporator. What may happen if you dont keep the unit filled with alcohol?
A. The S-cam may not rotate back when you release the brake pedal B. Ice may form in the air storage tanks and cause the brakes to fail C. Ice may form on the brake drums and warp them |
The most important thing to do when a low air pressure warning comes on is
A. Upshift B. Downshift C. Stop and safely park as soon as possible |
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Repeatedly pressing and releasing (fanning) the brake pedal may result in:
A. The loss of brake air pressure B. A build up of brake air pressure C. No change in brake air pressure |
If the spring brakes are on, when should you push the brake pedal?
A. Only when driving down a hill B. Only on a slippery road C. Never |
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If your vehicle has an alcohol evaporator, every day during cold weather your should:
A. Check and fill the alcohol level B. Change the alcohol from a new bottle C. Check the oil for alcohol content |
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?
A. Reduce your speed and drive to the nearest garage for repairs B. Reduce your speed and test the remaining system while driving C. Stop and safely park. Continue only after the system is fixed |
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It is not safe to drive a vehicle that has brake drums (or discs) with cracks or that are thinner than the manufacturers specifications, generally this will be _____ inch
A. 1/8 B. 1/4 C. 1/2 |
Air braking takes more time than hydraulic braking because air:
A. Brakes use different brake drums B. Takes more time to flow through the lines than hydraulic fluid C. Brakes require heavier return springs |
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Total stopping distance for vehicles with air brakes is longer than that for vehicles with hydraulic brakes due to ______ distance.
A. brake lag B. reaction C. effective braking |
If you must make an emergency stop, brake so you:
A. Use the hand brake before the brake pedal B. Can steer and your vehicle stays in a straight line C. Use the full power of the brakes to lock them |
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Emergency controlled braking is when you:
A. Apply the brakes as hard as you can without locking the wheels B. Brake as hard as you can, release the brakes when the wheels lock, and put the brakes back on again when the wheels start rolling C. Apply the hand valve for one second, then push hard on the brake pedal |
The use of air brakes on a downgrade is only a supplement to the:
A. Use of the spring brakes B. Use of the front brake limiting valve C. Braking effect of the engine |
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The proper method of braking when going down long and/or steep grades after selecting the proper gear, is to brake until your speed is about _______ miles per hour below your "safe" speed, then release your brakes
A. 5 B. 10 C. 15 |
You are on a steep downgrade and have reached your "safe" speed of 40 mph. You would apply the service brakes until your speed drops to _____ mph
A. 25 B. 30 C. 35 |
