| Question | Answer |
| When is it OK to leave your truck unattended without applying the parking brakes and choking the wheels? | Never |
| The stop light switch_______ | Turns on your brake lights to warn drivers behind you. |
| It is not safe to drive a vehicle that has brake drums with cracks longer than_______ of the width of the friction area. | 1/2 |
| To test air service brakes you should________. | Brake firmly while slowly moving forward. |
| A slack adjusters free play needs to be adjusted if it is more than about _________ when you pull on it? | 1 inch |
| If air pressure is not built up within the correct amount of time, then ___________? | Your air pressure may drop to a low point while driving, requiring an emergency stop. |
| The safety valve reduces pressure at _________ psi? | 150 |
| Why should you drain water from compressed air tanks? | Water can freeze in cold weather and cause brake failure. |
| If your vehicle has an alcohol evaporator, everyday during cold weather you should _________. | Check and fill the alcohol level |
| The air loss rate for a straight truck or bus with the engine off and the brakes on should not be worn more than ________. | 3 psi in one minute |
| The driver should be able to see a low pressure warning which comes on before pressure in the service air tanks falls below ________ psi? | 60 |
| The air brake lag distance at 55 mph on dry pavement adds about ________ feet? | 32 feet |
| If your truck has a properly functioning dual air brake system and minimum size air tanks the air pressure should build up from 85 to 100 psi within how many minutes? | 45 |
| How should you check that your service brakes are working properly? | Park on ground level, wait until normal air pressure is reached, release the parking brake and move forward slowly at 5 mph. Then apply the brakes firmly using the brake pedal. |
| A straight truck or bus air brake system should not leak at the rate of more than _________ psi per minute with the engine off and the brakes released. | 2 |
| Excessive use of the service brakes results in overwhelming which can lead to _______. | Expansion of the brake drums. |
| The safety valve is set automatically when pressure is _______. | 150 |
| If you must make an emergency stop, you should brake so you __________. | Can steer and so your vehicle stays in a straight line |
| 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? | Stop right away and safely park. Continue only after the system is fixed. |
| The brake pedal in an air brake system________. | Control the air pressure applied to put on the brakes. |
| All air brake equipped vehicles have _________. | A supply pressue gauge |
| With air brake vehicles, the parking brakes should be used _____________. | Whenever you leave the vehicle unattended |
| A straight truck or bus air brake system should not leak at the rate of more than ________ psi per minute with the engine off and the brakes released. | 2 |
| To check the free play of manual slack adjusters of S-cam brakes, you should park on ______? | Level ground, check the wheels and release the parking brakes |
| The use of brakes on a long and steep downgrade under normal conditions is only a supplement to _________? | The braking effect of the engine |
| The most important thing to do when a low air pressure warning comes on is ________? | Stop and safely park as soon as possible |
| The parking or emergency brake on a heavy vehicle can only be held on position by something that cannot leak away, like ____? | Spring pressure |
| Why drain water from compressed air tanks? | Water can freeze in cold weather and cause brake failure |
| Repeatedly partially releasing and pressing the brake pedal may result in _____? | A loss of brake air pressure |
| The brake system that applies and release the brakes when the driver uses the brake pedal is the __________ brake system. | Service |
| A slack adjusters free play needs to be adjusted if it is more than about ________ how many inches when you pull hard on it? | 1 inch |
| An air brake system is fully charged at what psi? | 125 |
| If the spring brakes are on, when would you push the brake pedal? | Never |
| When brakes are applied, the brake shoes will press against the ______? | Brake drum or disc |
| The safety valve discharges automatically at the pressure of _________? | 150 |
| Emergency stab braking is ________? | Press on the brake pedal as hard as you can, release the brakes when the wheels lock, put on the brakes again when the wheels start rolling |
| Why should you drain water from compressed air tanks? | Water can freeze in cold weather and cause barke failure |
| Modern air brake systems combine three different systems. They are the service, the parking and the ___________ brakes. | Emergency |
| If you do not have automatic tank drains, how often should you drain the oil and water from the bottom of compressed air storage tanks? | At the end of each day of driving |
| The proper use of the brakes when going down a long steep grade after selecting a proper gear is to brake until your speed is about ________ mph below the posted speed for your safety and release your brake | 15 mph |
