Air Brakes Flashcards
The air compressor governor controls? A The RPMs of the air compressor B whether the compressor is on or off C Air pressure applied to the brakes D when the compressor well pump air into the storage tanks
D when the compressor will pump air into the storage tanks
Which brake system applies and releases the break when the driver uses the brake pedal? A The emergency brake system B The service break system C The parking brake system D none of the above
B The service break system
When a failure occurs in the service break system the system you need to stop the vehicle is the? A parking brake system B The emergency brake system C drum brake system D The handbrake system
B The emergency brake system
Three different systems are found on a modern air brake system service breaks the parking brake and the? A emergency brakes B foot brakes C S – Cam brakes D drum brakes
A emergency brakes
If your vehicle has an alcohol evaporator it is there too?
A get rid of alcohol that condenses in the air tanks
B let the driver skip daily tank drainIng
C increase tank pressure the way superchargers boost engines
D reduces the risk of ice in the air brake valves in cold weather
D reduces the risk of ice in the airbrake valves in cold weather
Oil and water usually collect in compress it air tanks if you do not have automatic tank and drains when should you drain the air tanks? A after four hours of service B after every working day C once a week D every other week
B after every working day
The brake pedal:
A is the main lever in the system?
B can be a foot rest during normal driving
C Controls the air pressure applied to operate the service brakes
D excerpts force on the slack adjusters by rods and connectors
C Controls the air pressure applied to operate the service brakes
If your vehicle is equipped with an alcohol evaporator every day during cold weather you should?
A check infield the alcohol level
B change the alcohol from a new bottle
C Oil the system with 5 weight oil
D drain out the op alcohol which has accumulated
A check infield the alcohol level
Which of the following is okay defined in the air brake system? A oil B air C water D all of the above
B air
Why drain water from compressed air tanks?
A The low boiling point of water reduce braking power
B water can freezing cold weather and cause brake failure
C water over cools the compressor
D to keep from fouling up the air compressor
B water can freezing cold weather and cause brake failure
The most common type of foundation break found on have a commercial vehicles is: A disc B wedge and drum C s-cam drum D none of the above
C s-cam drum
The air supply pressure gauge shows the driver how much pressure: A has been used on this trip B is available in the air tanks C is being sent to the brake chambers D none of above
B is available in the air tanks
When using the parking brake or emergency brake what type of pressure is being used
A fluid pressure
B Spring pressure
C Air pressure
D any of the above
B Spring pressure
Airbrake equipment vehicles must have?
A at least three air tanks
B he hydraulic braking system in case the air system fails
C and air pressure gauge to show the pressure available for braking
D and air application gauge to show the pressure available for braking
C and air pressure gauge to show the pressure available for braking
You can tell if your vehicle is equipped with antilock braking system if there is a\_\_\_\_\_\_\_ malfunction lamp on the dashboard A red B blue C yellow D green
C yellow
The application pressure gauge shows the driver how much pressure A has been used on this trip B is in the air tanks C is being applied to the brakes D none of the above
C is being applied to the brakes
The vehicle must have a warning device which comes on when air pressure in the service air tanks falls below?
A 40 psi
B 55 psi
C 60 psi
D 80 psi
C 60 psi
During normal operations the parking an emergency brake are usually held back by? A Air pressure B Spring pressure C centrifugal force D bolts or clamps
A air pressure
What turns on the electrical stoplight switch in airbrake system? A Spring pressure B hydraulic pressure C Air pressure D The driver by hand
C Air pressure
In in airbrake equipped vehicle when do you use the parking brakes?
A when slowing down
B as little as possible
C whenever you park the vehicle
D only during pre-and post trip inspections
C whenever you park the vehicle
What will determine how effective the spring emergency brakes or the parking break or working?
A has nothing to do with the condition of the service breaks
B can only be tested by highly trained brake service people
C depends on the adjustment of the service brakes
D it increases when the service brakes are hot
C depends on the adjustment of the service brakes
If your truck or bus has dual parking control valve you can use pressure from a separate tank to?
A release the emergency brakes to move a short distance
B apply more brake pressure for stopping if the main tank is getting low
C stay parked without using up service air pressure
D balance the service break system while you drive
A release the emergency brakes to move a short distance
Your vehicle has dual air brake system if a little warning pressure comes on for the secondary system you should?
A stop safely park and continue only when the system is repaired
B reduce your speed and test the remaining system well underway
C reduce your speed and drive to the nearest garage for service
D continue at normal speed no action is needed when the secondary system fails
A stop safely parking continue only when the system is repaired
Of the choices below the first thing to do when a low pressure warning comes on is: A stop in safely park as soon as you can B upshift C adjust the brake pedal for more travel D Open the air supply control valve
A stop in safely park as soon as you can
When does the drivers manual advise disconnecting the steering axle brakes to help keep the unit straight? A never B when the road is slippery C when driving in very hilly areas D when towing a trailer that has brakes
A never
How would you use the stab breaking technique during an emergency braking?
A brake hard with the brake pedal and hand valve until stopped
B Brake hard with the pedal until the wheels lock then let off the brakes for a long as the wheels were locked
C Break hard with the pedal until the wheels lock then let off until the wheels are rolling again
D pump the brake pedal rapidly and lightly
C Break hard with the paddle until the wheels locked then let off until the wheels are rolling again
On a heavy vehicle the emergency brake is usually held in place by spring pressure because air pressure can leak away
A true
B false
A true
The color of the parking control knob on the dash of the vehicle is? A yellow B red C blue D green
A yellow
A tractor truck or bus equipped with antilock braking system\_\_\_\_\_\_\_\_ A decreases braking distance B increased braking distance C avoids wheel lock up D is used on wet pavement
C avoids wheel lock up
During normal driving parking & emergency brakes are usually held back by
A Spring pressure
B Air pressure
C centrifugal force
D hand valve
B Air pressure
How do you check at the free play on manual slack adjusters?
A stop on level ground and apply the emergency brakes
BPark on level ground Chuck the wheels release the parking brakes and pulled the slack adjuster
C Park on level ground and drain off air pressure before making adjustments
D apply the service breaks by hand at the brake chambers and watch the slack adjusters move
B Park on level ground chalk the wheels release the parking brakes and pulled the slack adjuster
The air leakage rate for a combination vehicle engine off brakes on should be less then_____PSI per minute?
A 1psi
B 2 psi
C 3 psi
D 4 psi
D 4 psi
With the engine off in the brakes released a combination vehicle airbrake systems should not leak more then how many PSI per minute?
A 1 psi
B 2 psi
C 3 psi
D 4 psi
C 3 psi
A straight truck or bus airbrake system cannot leak more then_____PSI per minute with the engine off and the brakes released?
A 1 psi
B 2 psi
C 3 psi
D 4 psi
B 2 psi
Air loss in a straight vehicle (not in a combination unit) should not be more than\_\_\_\_\_\_psi with the engine off in the brakes on? A 1 psi in 30 sec B 1 psi in 60 sec C 2 psi in 45 sec D 3 psi in 60 sec
D 3 psi in 60 sec
When should you test the parking brake? When the vehicle is:
A parked
B moving slowly
C going down hill
D moving at highway speed
A parked
You must make a quick emergency stop you should break it as you
A steer hard as you break hard
B use the full power of the brakes and lock them
C stay in a straight line and maintain steering control
D burn up in the handbrake first
C Stay in a straight line and maintain the steering control
To use the stab breaking technique during emergency braking you:
A pump the brake pedal rapidly and lightly
B Break hard with the pedal until the wheels lock and get off the break until the wheels begin rolling again
C Break hard with the pet on till the wheels lock up and get off the brakes for as long as the wheels are locked
D Break hard with the paddle and hand valve until you stop
B Break hard with the paddle until the wheels locked think it off the break until the wheels begin rolling again
You know when your brakes are feeding when
A you need more brake pressure to keep the same speed on a downgrade
B The brake pedal fades away when you press on it
C you get off the brake pedal and speed increases
D you need less pressure on the brake pedal for each stop
A you need more brake pressure to keep the same speed on a downgrade
Why should you not fan your brakes on and off during long downgrades
A Air usage is less when you fan
B brake linings do not get hot when fanning
C The short time off brakes it does not allow break cooling
D none of the above
C The short time off the brakes does not allow brake cooling
Air breaking takes more time than hydraulic breaking because air
A brakes use different brake drums
B takes more time to flow through the lines then hydraulic
C brakes require heavy year return springs
D is always leaking through airline fittings
B takes more time to flow through the lines then hydraulic
Which of the following makes the total stopping distance for airbrakes longer than that for hydraulic brakes A perception distance B reaction distance C Brake lag distance D effective braking distance
C Brake a lag distance
The brake system that applies and releases the brakes when the driver uses the brake pedal is the______Brake system
A emergency
B Service
C parking
D none of the above
B Service
The driver must be able to see a warning that is given when air pressure in the service air tanks falls below?
a 40 psi
B 50 psi
C 60 PSI
D 75 PSI
C 60 PSI
An airbrake systems safely relief valve opens at about?
A 40 psi
B 120 psi
C 150 psi
D 200 psi
C 150 psi
When some airbrakes in the system are doing more work and then others A those brakes will develop more heat B you may experience brake fade C vehicle handling will be affected D all of the above
D all the above
Your safety relief valve has opened several times this means_______
A The system is working properly
B Air pressure is probably low
C The system needs immediate attention
D The system needs flushed
C The system needs immediate attention
At what air pressure should the low air warning alarm come on
A 45 psi
B 25 psi
C must come on by 60 PSI
D 150 psi
C must come on by 60 PSI
With the brakes released on the single vehicle what is the allowable air loss
A four psi
B three PSI
C two psi
D One psi
C to psi
To test the compressor on a dual airbrake vehicle run the engine at a fast idle to charge the air system your gauge should be showed you
A pressure builds from 85 to 100 psi within three minutes
B your pressure builds from 85 to 100 psi within 45 seconds
C The compressor cuts out by 75 PSI
D none of the above applies
B your pressure builds up from 85 to 100 psi within 45 seconds
Spring breaks are held on by_________
A Air pressure
B electrical current
C forces other than air electrical or hydraulic
D The drivers hand valve
A air pressure
Most large vehicles with airbrakes have spring break which?
A are part of the parking brake systems operation only
B is part of the service break system only
C are part of both the parking in emergency brakes
D is part of the front suspensions only
C are part of both the parking emergency brakes
What color is the parking control knob on the dash of the vehicle
A red
B green
C yellow
D black
C yellow
What would cause all of the airbrake systems on the vehicle to have poor breaking power
A Low hydraulic fluid
B brakes being out of adjustment
C A broken air line
D Low too heavy
B breaks been out of adjustment
If a low air pressure warning comes on what should you do
A stop in safely park your vehicle soon as possible
B you can safely continue until you get to the next service center
C turn it off so that it will not distract you
D steer onto the left shoulder
A Stop at and safely park your vehicle as soon as possible
Operating a vehicle equipped with antilock brakes and helps you avoid wheel lock up
A true
B balls
A true
When only the tractor is equipped with ABS you should
A always pull a trailer equipped with ABS
B be able to maintain control in a skid
C be prepared to lose control
D disconnect the ABS on the tractor
B be able to maintain control in a skid
You still have a normal break functions if your ABS is not working
A true
B false
A true
