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AIR BRAKES PRACTICE TEST- A
- The parking or emergency brake on a heavy vehicle can only be held into position by something that cannot leak away. An example would be?
a. Fluid pressure b. Spring pressure c. Air pressure d. Any of the above
- A straight truck or bus air brake system would not leak at a rate of more than how many PSI per minute with the engine off and the brakes released?
a. 1 PSI per minute b. 2 PSI per minute c. 3 PSI per minute d. 4 PSI per minute
- Your vehicle has a dual air brake system, if a low air pressure warning comes on for the secondary system what should you do?
a. Bring the vehicle to a safe stop and continue only when the system is fixed b. Reduce your speed and test the remaining system while underway c. Reduce your speed and drive to the nearest garage for repairs d. Continue at normal speed if only the secondary system fails
- If your vehicle has an alcohol evaporator, why is it there?
a. To rid the wet tank of alcohol that condenses and sets at the bottom b. To eliminate the need for daily tank draining c. To boost the tank pressure in the same way that turbo chargers boost engines d. To reduce the risk of ice in air brake valves in cold weather
- Air braking takes more time than hydraulic braking because
a. Air brakes use different brake drums b. Air takes more time to flow through than hydraulic fluid c. Brakes require heavier return springs d. Air is always leaking through air line fittings
- The brake pedal in an air brake system ______________________.
a. Controls the speed of the air compressor b. Always needs to be held down half-way during normal driving c. Controls the air pressure applied to put on the brakes d. Is connected to slack adjusters by a series of rods and linkages
- If your truck or bus has dual parking control valves you can use pressure from a separate tank for what purpose?
a. To balance the service brake system when you are parked. b. To stay parked twice as long without using up the service air pressure. c. To release the spring emergency and parking brakes to move a short distance. d. To brake harder if the main tank is getting low.
- Air brake systems combine three different systems. They are the service brake system, the parking brake system, and what other?
a. The emergency brake system b. The foot brake system c. The S-CAM brake system d. The drum brake system
- To check the free play of manual slack adjusters of S-CAM brakes you should park on what kind of grade?
a. Park on level ground and apply the parking brake b. Park on level ground, chock the wheels and release the parking brakes c. Park on level ground, drain off the air pressure before checking the adjustment d. Park on a slight grade, release the parking brakes and apply the service brake watching your vehicle movement
- Which of these is the most important thing to do when a low air pressure warning comes on.?
a. Stop and safely park as soon as possible b. Shift to the next higher gear c. Adjust the brake pedal for more travel d. Open the air supply control valve
- What does the air compressor governor do?
a. It controls the speed of the air compressor b. It controls when the brake chambers release pressure c. It controls the air pressure applied to the brakes d. It controls when air is pumped into the air tanks
- The braking power of the spring brakes ___________________.
a. Is not affected by the condition of the service brakes b. Can only be tested by highly trained brake service people c. Depends on the service brakes being in adjustment d. Increases when the service brakes are hot
- All air brake equipped vehicles have _____________________.
a. At lease one brake heater b. A hydraulic system in case the air system fails c. A supply pressure gauge d. An air use gauge
- What is the correct braking technique for driving on long downhill grades?
a. Reduce your speed to 5 MPH below your safe speed b. Release the brakes c. When your speed has increased to your safe speed, repeat a and b d. All of the above
- The driver must be able to see or hear a warning before air pressure in the storage tanks falls below what pressure?
a. 40 PSI b. 50 PSI c. 60 PSI d. 80 PSI
- During normal driving, spring brakes are usually held back by ______.
a. Bolts b. Air Pressure c. Spring Pressure d. Centrifugal force
- In air brake vehicles the parking brakes should be used how?
a. As little as possible b. Anytime the vehicle is parked c. To hold your speed when going downhill d. Only during pre-trip and post-trip inspections
- Emergency stab braking is when you ____________.
a. Press hard on the brake pedal and apply full hand valve until you stop b. Apply the hand valve for one second, then push hard on the pedal c. Use light, steady pressure on the brake pedal d. Brake as hard as you can, release the brakes when the wheels lock; and when the wheels start rolling press the brakes fully
1 - (b) 6 - (c) 11 - (d) 16 - (b) 21 - (d) ADD FROM TEST B #3, 2 - (b) 7 - (c) 12 - (c) 17 - (a) 22 - (c) 3 - (a) 8 - (a) 13 - (c) 18 - (d) 23 - (b) 4 - (d) 9 - (b) 14 - (c) 19 - (b) 24 - (b) 5 - (b) 10 - (a) 15 - (c) 20 - (d) 25 - (d)
AIR BRAKES PRACTICE TEST- B
- The air loss rate for a straight truck or bus, with the engine off and the brakes on, should not be more than what?
a. 1 PSI in 30 seconds b. 1 PSI in 1 minute c. 2 PSI in 45 seconds d. 3 PSI in 1 minute
- Your brakes are fading when _________.
a. You have to push harder on the brake pedal to control your speed on a downgrade. b. The brake pedal feels spongy when you apply pressure. c. You release pressure on the brake pedal and speed increases. d. Less pressure is needed on the brake pedal for each stop.
- What does the supply pressure gauge show?
a. It shows how much pressure you have used in this trip. b. It shows how much pressure is in the air tanks. c. It shows how much pressure is going to the brake chambers. d. It shows how much pressure the air can take.
- The brake system that supplies and releases the brakes when the driver uses the brake pedal is called what brake system?
a. The emergency brake system b. The service brake system c. The parking brake system d. None of the above
- If your vehicle has an alcohol evaporator, every day during cold weather what should you do?
a. Check and fill the alcohol level b. Change the alcohol from a new bottle c. Clean the air filter with alcohol d. Check the oil for alcohol content
- Why should you drain water from compressed air tanks?
a. The boiling point reduces braking power. b. Water can freezes in cold weather causing brake failure. c. Water-cools the compressor too much. d. You should drain water to make room for the oil that should be in the compressed air tank.
- To test air service brakes you should brake firmly when moving slowly forward. What tells you that the brakes are O.K.?
a. A delayed stopping action. b. An unusual feel. c. The vehicle pulls to the right. d. None of the above.
- Parking or emergency brakes of trucks and buses are held on by what kind of pressure?
a. Spring pressure b. Fluid pressure c. Air pressure d. Atmospheric pressure
- The driver must be able to see a low air pressure warning, which comes on before pressure in the service air tanks falls below how many PSI?
a. 20 PSI b. 40 PSI c. 60 PSI d. 80 PSI
- If your vehicle has an alcohol evaporator, why is it there?
a. To rid the wet tank of alcohol that condenses and sets at the bottom b. To eliminate the need for daily tank draining c. To boost the tank pressure in the same way that turbo chargers boost engines d. To reduce the risk of ice in air brake valves in cold weather
- The brake pedal in an air brake system _________________.
a. Controls the speed of the air compressor b. Is seldom used compared to hydraulic systems c. Controls the sir pressure applied to put on the brakes d. Is connected to slack adjusters by a series of rods and linkages
- If your truck or bus has dual parking control valves then you can use pressure from a separate tank for what purpose?
a. To balance the service brake system when you are parked. b. To stay parked twice as long without using up the service air pressure. c. To release the spring emergency and parking brakes to move a short distance. d. To brake harder if the main tank is getting low.
- If you must make an emergency stop than you should brake how?
a. So that you use the hand brake before the brake pedal b. So that you do not need to worry about steering c. So you can steer and so your vehicle stays in a straight line d. So you can use the full power of the brakes to lock the wheels
- To check the free play of manual slack adjusters of S-CAM brakes you should park on what kind of grade?
a. Level ground and apply the parking brake b. Park on level ground, chock the wheels and release the parking brakes c. Park on level ground, drain off the air pressure before checking the adjustment d. Park on a slight grade, release the parking brakes and apply the service brake watching your vehicle movement
- The most important thing to do when a low air pressure warning comes on is what?
a. Up shift b. Downshift c. Adjust the brake pedal for more travel d. Stop and safely park as soon as possible
- What does the air compressor governor control?
a. The speed of the air compressor b. Air pressure applied to the brakes c. Air pumped into the air tanks d. When the brake chambers release pressure
- What describes the braking power of the spring brakes?
a. It increases when the service brakes are hot b. It depends on the service brakes being in adjustment c. It is not affected by the condition of the service brakes d. It can only be tested by highly trained brake service people
- All air brake equipped vehicles have what?
a. An air use gauge b. A supply pressure gauge c. At least one brake heater d. A back-up hydraulic system
1 - (d) 6 - (b) 11 - (c) 16 - (c) 21 - (b) 2 - (a) 7 - (d) 12 - (c) 17 - (d) 22 - (d) 3 - (b) 8 - (d) 13 - (a) 18 - (c) 23 - (c) 4 - (b) 9 - (d) 14 - (b) 19 - (c) 24 - (b) 5 - (a) 10 - (a) 15 - (a) 20 - (c) 25 - (b)
- To check the free play of manual slack adjusters of S-CAM brakes, you should park on level ground, chock the wheels, and release the parking brake.
- The most important thing to do when a low air pressure warning comes on is stop and safely park as soon as possible.
- The air compressor governor controls when air is pumped into the air tanks.
- The braking power of the spring brakes depends on the service brakes being in adjustment.
- All air brake equipped vehicles have a supply pressure gauge.
- If you must make an emergency stop, you should brake so you can steer and so your vehicle stays in a straight line.
- The parking or emergency brake on a heavy vehicle can only be held in position by something that cannot leak away, like spring pressure.
- A straight truck or bus air brake system should not leak at a rate of more than 2 PSI per minute with the engine off and the brakes released.
- Your vehicle has a dual air brake system. If a low air pressure warning comes on for the secondary system, you should bring the vehicle to a safe stop and continue only when the system is fixed.
- Air braking takes more time than hydraulic braking because air takes more time to flow through the lines than hydraulic fluid.
- Air brake systems combine three different systems. They are the service, parking, and the emergency brake systems.
- The application pressure gauge shows how much air pressure you are applying to the brakes.
- If you do not have automatic tank drains, you should drain the oil and water from the air storage tanks at the end of each day of driving.
