ID CDL AIR BRAKES TEST

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ID CDL AIR BRAKES TEST

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -99 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation

Question 1: How can you check the slack adjusters?

• Park on level ground, turn off the parking brakes, and pull hard on each slack adjuster. It

shouldn't move more than one inch.

• Park on an incline and see if the vehicle rolls.
• Park on level ground, turn off the parking brakes, and press the brake pedal.

Answer:

• Park on level ground, turn off the parking brakes, and pull hard on each slack adjuster. It shouldn't

move more than one inch.

Question 2: What factors can cause brakes to fade or fail?

• Overheating, low air pressure, and not relying on the engine braking effect
• Not pressing the brake pedal hard enough
• Not taking your foot off the accelerator

Answer:

• Overheating, low air pressure, and not relying on the engine braking effect

Question 3: Converter dollies built on or after March 1, 1998 are required to have anti-lock brakes. These dollies will have

• a yellow malfunction lamp in the center of the dolly.
• a yellow malfunction lamp on the right side of the dolly.
• a yellow malfunction lamp on the left side of the dolly.

Answer:

• a yellow malfunction lamp on the left side of the dolly.

Question 4: The brake pedal in an air brake system

• is connected to slack adjusters by a series of rods and linkages.
• controls the speed of the air compressor.
• controls the air pressure applied to the brakes.

Answer:

• controls the air pressure applied to the brakes

Question 5: You know that your brakes are fading when

• pressure on the brake pedal is released and speed increases.
• the brake feels spongy when pressure is applied.
• you have to press the brake pedal harder to control speed on a downgrade.

Answer:

• you have to press the brake pedal harder to control speed on a downgrade

Question 6: The driver must be able to see a low pressure warning, which comes on before pressure in the service air tank falls below ___ psi.

• 80
• 100
• 60

Answer:

• 60

Question 7: The braking power of the spring brakes

• increases when the service brakes are hot.
• is not affected by the condition of the service brakes.
• depends on the service brakes being in adjustment.

Answer:

• depends on the service brakes being in adjustment

Question 8: If a malfunction causes the the air compressor to stop working,

• you will still have enough air in the storage tanks to apply the air brakes several times.
• you will have just enough air in the storage tanks to apply the air brakes once.
• you will be unable to use the air brakes and will have to resort to spring or emergency brakes.

Answer:

• you will still have enough air in the storage tanks to apply the air brakes several times

Question 9: If the air compressor should develop a leak, what keeps the air in the tanks?

• The tractor protection valve
• The one-way check valve
• The emergency relay valve

Answer:

• The one-way check valve

Question 10: How can you tell if your vehicle is equipped with an anti-lock braking system

(ABS)?

• The vehicle was manufactured after 1998.
• ABS is still optional.
• The vehicle was manufactured after 2010.
• The vehicle was manufactured after 2000.

Answer:

• The vehicle was manufactured after 1998

Question 11: What is the best way to test your vehicle's low air pressure warning signal?

• Pump the brakes until the air pressure drops below 30 psi.
• Pump the brakes while your vehicle is fully on.
• With the engine off, step on and off the brake pedal to lower the air pressure below 60 psi.
• Manually let the air out of your brakes and see if the signal comes on.

Answer:

• With the engine off, step on and off the brake pedal to lower the air pressure below 60 psi.

Question 12: The brake system that applies and releases the brakes when the driver presses the brake pedal is the ________ brake system.

• service
• emergency
• parking

Answer:

• service

Question 13: The parking or emergency brake on a heavy vehicle can only be held in position by something that cannot leak away, like

• hydraulic pressure.
• spring pressure.
• air pressure.

Answer:

• spring pressure

Question 14: 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.

• 35
• 25
• 30

Answer:

• 35

Question 15: If air pressure is not built up fast enough,

• the alcohol container may be low.
• you should be ready to use your parking brakes to stop.
• the air pressure may drop too low during driving.

Answer:

• the air pressure may drop too low during driving

Question 16: To drive a tractor-trailer with air brakes, you must have

• a Class A CDL without an air brakes restriction.
• any CDL without an air brakes restriction.
• a Class A CDL.

Answer:

• a Class A CDL without an air brakes restrictions

Question 17: Brake linings (friction material) must not be worn dangerously thin (i.e., less than _______ in thickness).

• 1/2 inch.
• 1/3 inch.
• 1/4 inch.

Answer:

• 1/4 inch

Question 18: It is not safe to drive a vehicle that has brake drums with cracks that are longer than ____ of the width of the friction area.1/4 1/2 5/16

Answer:

• 1/2