• ASD Air Brakes Practice Test

  • The driver must be able to see a warning before air pressure in the service air tanks falls below*
  • To check the brake slack on S-cam brakes , you should park on*
  • The air brake system for a straight truck or bus should not leak at a rate of more than _______ psi per minute with the engine off and the brakes released*
  • The air loss rate for a straight truck or bus with the engine off and the brake on should not be more than*
  • If your vehicle has an alcohol evaporator, it is there to*
  • How should you check that your service brakes are working properly?*
  • The air supply pressure gauge shows how much pressure*
  • Why should you drain water from compressed air tanks?*
  • The safety valve is set to automatically reduce pressure at ___ psi*
  • If air pressure does not build up fast enough within the correct amount of time*
  • How should you check that the spring brakes come on when air pressure in the system drops below a certain level?*
  • For air brake systems in good condition, the air compressor should start pumping at about ____ psi*
  • To test air service brake, you should*
  • If you do not have automatic tank drains, how often should you drain the oil and water from the bottom of the compressed air storage air tanks?*
  • When you apply the brakes, the brake shoes/linings are pressed against the:*
  • With air brake vehicles, the parking brakes should be used:*
  • All air brake equipped vehicles have*
  • The parking or emergency brake on a heavy vehicle can only be held in position by something that cannot leak away, such as:*
  • The parking or emergency brakes of trucks and buses can be legally held on by________ pressure*
  • Modern air brake systems are three different systems combined together. They are the service, parking, and the*
  • The stop light switch*
  • If your truck has a dual air brake system and one of the systems is low on pressure:*
  • The braking power of the spring brakes:*
  • The application pressure gauge shows how much air pressure you:*
  • Before driving a truck or bus with a dual air brake system, the pressure in each system should be at least _____ psi*
  • If your truck or bus has dual parking control valves, you can use pressure from a separate tank to*
  • The brake pedal in an air brake system*
  • What is the first thing you should do when a low air pressure warning comes*
  • The S-cam*
  • When is it okay to leave your truck unattended without applying the parking brake or chocking the wheels?*
  • In air brake vehicles, the parking brakes should be used*
  • The modulating control valve allows you to control the*
  • The brake system that applies and releases the brakes when the driver uses the brake pedal is the ______ brake system.*
  • Some air brake systems have an alcohol evaporator. What may happen if you don't keep the unit filled with alcohol?*
  • Under normal conditions, to engage the parking brake the driver must first*
  • During normal driving, spring brakes are usually held back by*
  • If your vehicle has an alcohol evaporator, every day during cold weather you should*
  • The most common type of foundation brake found on heavy vehicles is the*
  • A supply pressure gauge tells you how much pressure is in the*
  • The air compressor governor controls*
  • It is not safe to drive a vehicle that has brake drums (or discs) with cracks or that are thinner than the manufacturers specifications. Generally this will be ____ of an inch*
  • Your truck or bus has a dual air brake system. If a low air pressure warning comes on for only one system, what should you do?*
  • Your truck has a properly functioning dual air brake system and minimum size air tanks. The air pressure should build from 85 to 100 psi within ________ seconds*
  • If the spring brakes are on, when should you push the brake pedal?*
  • A truck with air brakes going 55 mph would require a stopping distance of*
  • The spring brakes used on tractors and straight trucks will bring your truck to a stop when the air pressure drops below*
  • The air brake lag distance at 55 mph on dry pavement adds about ____ feet to your stopping distance.*
  • Excessive heat in the brakes can cause the*
  • 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*
  • Air braking takes more time than hydraulic braking because air*
  • Total stopping distance for vehicles with air brakes is longer than that for vehicles with hydraulic brakes due to ___________ distance.*
  • The use of air brakes on a downgrade is only a supplement to the*
  • The proper method of braking when going down long and/or steep grades after selecting the proper gear, is to brake until your speed is about ____ mph below your "safe" speed, then to release your brakes*
  • Which of these is not a proper time to apply the parking brakes?*
  • You should know your brakes are fading when*
  • What is emergency stab braking?*
  • The most important thing to do when a low air pressure warning comes on is*
  • If you must make an emergency stop, brake so you*
  • Repeatedly pressing and releasing (fanning) the brake pedal may result in*
  • Emergency controlled braking is when you*
  • Which of the following about antilock braking systems is true?*
  • An air brake system is fully charged at _____ psi*
  • If a tractor, or bus has antilock brakes, it will have a _______ ABS malfunction lamp on the instrument panel*
  • If your truck's air compressor has its own oil supply, when should you first check the oil level?*
  • A slack adjuster probably needs to be adjusted if it moves more than about _____ inch when you pull hard on it*
  • To check the free play of manual slack adjusters on S-cam brakes, you should park on:*
  • Excessive use of the service brakes results in overheating, which can lead to:*

  • You have completed the practice test

     

    After your submission you will see your test results on the next page, with your percentage score at the bottom. On the questions you got wrong, you will see the correct answer in parentheses. Please review your results and continue to test until you can achieve 90% or better.

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