Which of the following steps should you use to check the slack adjusters on S Cam brakes?
Correct answer(s):
- Use gloves and pull hard on each slack adjuster
Topic
Air Brakes Test
If you plan on driving any CMV equipped with air brakes, you must take and pass the air brakes test to remove the air brakes restriction from your CDL. The air brakes test is different than the endorsement tests because the air brakes test works as a restriction instead of an endorsement. If you do not pass the air brakes test, your CDL will bear a mark of restriction which means that you are not authorized to drive a CMV with air brakes.
Quizzes in Air Brakes Test
What is the typical air pressure of a fully charged air brake system?
Correct answer(s):
- 125 psi
What is the proper way to test the air leakage rate?
Correct answer(s):
- Turn off the engine and release the parking brake
What is stab braking?
Correct answer(s):
- Applying your brakes until the wheels lock up, releasing, and then reapplying when the wheels start rolling
Why do air brakes take longer to stop than hydraulic brakes?
Correct answer(s):
- It takes longer for the air to flow through the lines
What will happen if your air compressor stops?
Correct answer(s):
- You'll still have air pressure left in the air tanks to stop
How should you check your air compressor governor “cut in” and “cut out” pressures?
Correct answer(s):
- Run the engine at a fast idle
- Step on and off the brake to reduce tank pressure
- Monitor the air pressure gauge
How fast should the air pressure build in a dual air system?
Correct answer(s):
- From 85 to 100 psi in 45 seconds
What are the typical air compressor governor cut-in and cut-out pressures?
Correct answer(s):
- Cut-in: 100 psi; Cut-out: 125 psi
What device will keep air in the tanks if the air compressor develops a leak?
Correct answer(s):
- The one way check valve
Which of the following devices indicates how much pressure you have in your air tanks?
Correct answer(s):
- Supply pressure gauge
Which of the following statements regarding spring brakes is true?
Correct answer(s):
- Spring brakes are held by mechanical force
At what air pressure must the low air pressure warning signal come on?
Correct answer(s):
- 60 psi
Which of the following statements is true regarding front wheel braking?
Correct answer(s):
- Front wheel braking is good under all conditions
Which of the following is the most common type of foundation brake?
Correct answer(s):
- S-cam drum brake
What psi level is the safety relief valve set to open at?
Correct answer(s):
- 150 psi
What is the alcohol evaporator’s primary purpose?
Correct answer(s):
- Put alcohol into the air system
What is the name of the device that pumps air into the air storage tanks?
Correct answer(s):
- Air compressor
What are the three types of brake systems used in a commercial vehicle air brake system?
Correct answer(s):
- Service brake, parking brake, emergency brake
What type of air do air brakes use?
Correct answer(s):
- Compressed air