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19 Cards in this Set
- Front
- Back
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Why must air tanks be drained? |
To expel water and oil from the compressed air in the air brake system |
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What is a supply pressure gauge used for? |
Shows how much pressure is in the air tanks |
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All vehicles with air brakes must have a low air pressure-warning signal. True or False? |
True. A visible warning signal must come on before the air pressure in the tanks fall below 60 psi. The warning is usually a red light but could be a mechanical arm (“wig wag”) that drops into your view. |
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What are spring brakes? |
A mechanical brake activator used as an emergency and parking brake |
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Front wheel brakes are good under all conditions. True or False? |
True |
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How do you know if your vehicle is equipped with anti-lock brakes? |
The vehicle will have a yellow ABC malfunction lamp |
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What is a dual air brake system? |
A dual air brake system has two separate air brake systems, which use a single set of brake controls. Each system has its own air tanks, hoses, lines, etc. One system typically operates the regular brakes on the rear axle or axles. The other system operates the regular brakes on the front axle (and possibly one rear axle). |
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What are slack adjusters? |
A safety feature found on S-cam brakes that reduces brake slack |
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How can you check slack adjusters? |
Park on level ground and chock the wheelsRelease the parking brakesTest slack adjuster for movement (1” maximum) |
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How can you test the low-pressure warning signal?Shut off engine |
1.Shut off engine 2.Turn on electrical power and step on and off the brake pedal (bleed off air) 3.Low-pressure signal should come on before the pressure drops to less than 60 psi in the air tank |
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How can you check that the spring brakes come on automatically? |
1.Park on level ground and chock the wheels 2.Release the parking brake 3.Shut off engine 4.Bleed off air as stated above |
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What are the maximum leakage rates? |
Single Vehicle 2 PSI/Minute Brake off Single Vehicle 3 PSI/Minute Brake on (Apply 90 psi or more) Combo Vehicle 3 PSI/Minute Brake off Combo Vehicle 4 PSI/Minute Brake on (Apply 90 psi or more) |
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Why should you be in the proper gear before starting down a hill? |
To utilize the braking effect of the engine |
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What factors can cause brakes to fade or fail? |
Excessive heat caused by using brakes too much and not relying on the engine braking effect |
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The use of brakes on a long, steep downgrade is only a supplement to the braking effect of the engine. True or False? |
True |
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If you are away from your vehicle for only a short time, you do not need to use the parking brake. True or False? |
False. Any time you park, use the parking brakes except if the brakes are very hot or if the brakes are very wet in freezing temperatures. |
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How often should you drain air tanks? |
Drain air tanks at the end of each working day unless the vehicle has automatic air tank drains. |
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How do you brake when you drive a tractor-trailer combination with ABS? |
As you always have or in other words:Use only the braking force necessary to stop safely and stay in control. Brake the same way, regardless of whether you have ABS on the tractor, the trailer, or both. As you slow down, monitor your tractor and trailer and back off the brakes (if it is safe to do so) to stay in control |
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You still have normal brake functions if your ABS is not working. True or False? |
True. Drive normally but get the system serviced soon. |
