• ASD Air Brakes Study Material

  • This is the study material for the Air Brakes test. Please study it until you are comfortable with the material, and then proceed to the practice tests. 

  • 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*
  • 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 instrument panel*
  • Which of the following about antilock braking systems is true?*
  • 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*
  • Excessive use of the service brakes results in overheating, which can lead to:*
  • To check the free play of manual slack adjusters on S-cam brakes, you should park on:*
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  • This is the study material for the Air Brakes test. Please study it until you are comfortable with the material, and then proceed to the practice tests.

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