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Why must air tanks be drained? |
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To drain moisture and oil out of the tank |
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What is a supply pressure gauge used for? |
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To tell you how much air is in the air tank. |
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All vehicles with air brakes must have a low air pressure warning signal. |
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True |
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What are spring brakes? |
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If the airbrakes leak down, springs press the brakes on to stop the vehicle. |
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Front wheel brakes are good under all conditions. |
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True |
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When you put your brakes on the air brake system works with an electric switch, by air pressure to turn on the brake lights. |
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True |
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What do air brakes use to make the brakes work? |
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Compressed air |
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Air brakes are really three different braking systems: service brake, parking brake and emergency brake. |
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True |
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The service brake applies and releases: |
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The brake when you use the brake pedal during normal driving. |
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The parking brake applies and releases: |
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The parking brakes when you use the parking brake control. |
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The emergency brake system: |
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Uses parts of the service and parking brake system to stop the vehicle in the event of a brake system failure. |
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The governor controls when the air compressor will pump into the air storage tanks. |
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True |
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The air storage tanks are used to hold compressed air. |
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True |
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When you put on the brakes by pushing down the brake pedal: |
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Air pressure is applied to the brake pads. |
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The S-cam forces the brake shoes away from one another and presses them
against the inside of the brake drum. It is called the S-cam because: |
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It is shaped like the letter S. |
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What is a dual air brake system? |
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A two brake system, one operates the front brakes and one operates the back brakes. |
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What are the slack adjusters? |
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It is an adjusting nut on the backside of the brake drum used for adjusting the brakes. |
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How can you check the slack adjuster? |
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Park on level ground, turn off parking brakes, pull hard on each slack adjuster. It shouldn't move more than one inch. |
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How can you test the low pressure warning signal? |
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Shut off the engine with enough air pressure, turn on the electrical
power and step on and off the brake pedal until the low air pressure
warning signal comes on. |
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What can you check to see if the spring brakes come on automatically? |
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Step on and off the brake, with the engine off, the parking brake knob should pop out when air pressure falls between 20-40 psi. |
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What are the maximum leakage rates? |
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Less than two psi in one minute for single vehicles and less than three psi in one minute for combination vehicles. |
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Should you ever leave your vehicle unattended without applying parking brakes or chocking the wheels? |
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No |
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If you are away from your vehicle only a short time, you don't need to use the parking brake. |
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False |
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How often should you drain air tanks? |
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Daily |
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The use of brakes on a long steep downgrade is only a supplement to the braking effect of the engine. |
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True |
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What factors can cause brakes to fade or fail? |
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A. Not pressing the brake pedal hard enough.
B. Over heating, low air pressure, and not relying on the engine braking effect.
C. Not taking your foot off the accelerator pedal. |
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Why should you be in the proper gear before starting down a hill? |
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So you only have to apply the brake just hard enough to feel a definite slowdown. |
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If oil and water collect in the air tanks what can happen to the brakes? |
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The brakes could fail. |
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What is the purpose of an alcohol evaporator? |
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To reduce the risk of ice in the brake valves and other parts in cold weather. |
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What is another name for controlled braking? |
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Squeeze braking |
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