CDL SECTION 5; AIR BRAKES EXAM QUESTIONS

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CDL SECTION 5; AIR BRAKES EXAM QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -16 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation Question 1: If you are away from your vehicle only a short time, you don't need to use the parking brake.

Answer:

False Question 2: All vehicles with air brakes must have a low air pressure warning signal

Answer:

True

Question 3: How often should you drain air tanks?

Answer:

Drain your air tanks at the end of each working day to remove moisture and oil. Otherwise your brakes could fail.

Question 4: What is a dual air brake system?

Answer:

A dual air brake system has two separate air systems which use a single set of brake controls. One system operates the regular brakes on the rear axle or axles. The other system operates the regular brakes of the front axle (and possibly one rear axle). Both systems supply air to the trailer (if there is one). The first system is called the primary system. The second is called the secondary system.

Question 5: What are the slack adjusters?

Answer:

Slack adjusters control the braking power. Too much brake slack can be very hard to stop.

Question 6: What are spring brakes?

Answer:

When the air pressure is removed the springs put on the brakes. A parking brake control in the cab allows the driver to let the air out of the brakes.Question 7: When the air pressure is removed the springs put on the brakes. A parking brake control in the cab allows the driver to let the air out of the brakes.

Answer:

True

Question 8: How can you test the low pressure warning signal?

Answer:

Shut the engine off when you have enough air pressure so that the low pressure warning signal is not on. Turn the electrical power on and step on and off the brake pedal to reduce air tank pressure. The low air pressure warning signal must come on before the pressure drops to less than 60 psi on the air tank(or tank with the lowest air pressure, in dual air systems). If the warning signal doesn't work you could lose air pressure and you would not know it.

Question 9: How can you check slack adjusters?

Answer:

Turn off the parking brakes so you can move the slack adjusters. Use gloves and pull hard on each slack adjuster so that you can get to it. If a slack adjuster moves more than about one inch where the push rod attaches to it, it probably needs adjustment.Question 10: The use of brakes on a long steep downgrade is only a supplement to the braking effect on the engine

Answer:

True

Question 11: Why must air tanks be drained?

Answer:

Water and compressor oil can get inside of the tank and can freeze in cold weather and cause brake failure.

Question 12: What is a supply pressure gauge used for?

Answer:

It tells you how much pressure is in the air tanks

Question 13: What can you check that the spring brakes come on automatically?

Answer:

Clock the wheels, release the parking brakes when you have enough air pressure to do it, and shut the engine off. Step on and off the brake pedal to reduce the air tank pressure. The parking brake knob should pop out when the air pressure falls to the manufacurers specification (usually between 20-40 psi). This causes the spring brakes to come on

Question 14: Why should you be in the proper gear before starting downhill?

Answer:

You will not be able to shift into lower fear after your speed has already built up. And all our engine braking effect will be lost.

Question 15: What factors can cause brakes to fade or fail?

Answer:

Brakes can fade or fail from excessive heat caused by using them too much and not relying on the engine braking effect.

Question 16: What are the maximum leakage rates?

Answer:

Less than 2 PSI n one minute for single vehicles and less than 3 PSI in one minute for combination vehicles.