/. Air brake systems combine what three different systems? - Answer-Service brakes,
parking brakes and emergency brakes.
/.When should you drain the air tanks? - Answer-After every working day.
/.Why drain water from the compressed air tanks? - Answer-Water can freeze in cold
weather and cause brake failure.
/.Air brake equipped vehicles must have: - Answer-A supply pressure gauge and
warning signal when psi drops below 60.
/.What can legally hold a parking or emergency brake in position for a truck, truck tractor
or bus? - Answer-Spring pressure.
/.What makes the total stopping distance for air brakes longer than that for hydraulic
brakes? - Answer-Brake lag distance.
/.The first thing you should do when the low air pressure warning comes on? - Answer-
Stop and safely park ASAP.
/.The braking power of the spring brakes: - Answer-Depends on the adjustment of the
service brakes.
/.The air compressor governor controls what? - Answer-When air is pumped into the air
tanks.
/.The application pressure gauge shows the driver how much pressure: - Answer-Is
being applied to the brakes.
/.When you apply pressure to the brake pedal, you are... - Answer-Pushing against a
spring and against air pressure to the brakes.
/.The air compressor is connected to the engine through... - Answer-Gears or a V-belt
/.Which type of brake is the most common in commercial vehicles? - Answer-S-cam
brake
/.An application pressure gauge... - Answer-Shows how much air pressure you are
applying to the brakes.
/.All vehicles with air brakes are required to have a low pressure warning signal. This
could be... - Answer-A red light, wig wag mechanical arm or a buzzer.
, /.To test service brakes you should... - Answer-Release the parking brake, move
forward slowly and depress brakes.
/.Stab braking occurs when you... - Answer-1. Press on a brake pedal as hard as you
can. 2. Release the brakes when the wheels lock up. 3. Apply the brakes when the
wheels start rolling.
/.Air brakes take longer to stop than hydraulic brakes because... - Answer-It takes
longer for the air to flow through the lines.
/.The proper way to go down long grades is to... - Answer-Apply brakes just hard
enough to reduce speed to 5 mph below safe speed then release until back to safe
speed and repeat process.
/.When should you avoid using the parking brake? - Answer-When the brakes are hot.
/.If your vehicle has an alcohol evaporator, everyday during cold weather you should: -
Answer-Check and fill the alcohol level.
/.During normal driving, spring brakes are usually he'd back by what? - Answer-Air
pressure
/.In air brake vehicles, the parking brakes should be used when? - Answer-Whenever
the vehicle is parked.
/.The brake pedal in an air brake system does what? - Answer-Controls the air pressure
applied to put on the brakes.
/.If your bus has dual parking control valves it means that you can use pressure from a
separate tank to: - Answer-Release the spring brakes to move a short distance.
/.A straight truck or bus air brake system should not leak at a rate of more than ____
PSI per minute with the engine off and the brakes released. - Answer-2
/.An alcohol evaporator does what? - Answer-Reduces the risk of ice in the air brake
valves in cold weather.
/.If you must make an emergency stop, you should brake so that you: - Answer-Stay in
a straight line and can steer.
/.Air loss should not be more than ___ with the engine off and brakes released. -
Answer-2 psi per minute
/.Stab braking - Answer-Brake as hard and you can, get off the the breaks when wheels
are locked, get back on the brakes when wheels start rolling again.