B.C. Class 1 Knowledge Practice Test 2026: Test de práctica 4

Test de práctica 4 de 5 de B.C. Class 1 Knowledge Practice Test: 25 preguntas más con respuestas y explicaciones.

Vehículo comercial
Columbia Británica
130 preguntas
Revisado el 10 de octubre de 2026

Pregunta 1 de 25
In this air brake diagram, what is the job of the air compressor?
- To remove water from the tanks
- To pump air into the storage tanks
- To measure push rod stroke
- To apply the parking brake
Ver respuesta
Respuesta: B. To pump air into the storage tanks
The engine-driven compressor pumps air into the tanks.
Pregunta 2 de 25
Since April 1, 2000, which trailers must have anti-lock brakes in Canada?
- Only trailers under 1,000 kg
- No trailers; only the tractor needs it
- Only boat and recreational trailers
- Commercial trailers with air brakes
Ver respuesta
Respuesta: D. Commercial trailers with air brakes
ABS is mandatory on commercial trailers with air brakes, and on trucks and buses over 4,560 kg built since April 1, 2000.
Pregunta 3 de 25
Why do you check for air leaks with the brakes applied?
- Leaks drain air quickly just when you need the brakes
- To test that the horn works on air
- To warm up the engine before driving
- To check the tire pressure on each wheel
Ver respuesta
Respuesta: A. Leaks drain air quickly just when you need the brakes
Leaks reduce the air available for braking, and they get worse when the system is under pressure.
Pregunta 4 de 25
Why are spring brakes used for parking?
- They are the only brakes fitted to the trailer
- They hold mechanically, without needing air in the system
- They are stronger only while the engine runs
- They use less fuel than the service brakes
Ver respuesta
Respuesta: B. They hold mechanically, without needing air in the system
Service brakes rely on air pressure, which can leak away. Spring brakes hold with spring force.
Pregunta 5 de 25
Before you drive, the air gauge shows low pressure. What should you do?
- Drive off and let it build while moving
- Drain the tanks and start again
- Let the pressure build to normal before moving
- Release the spring brakes by hand
Ver respuesta
Respuesta: C. Let the pressure build to normal before moving
Do not move until the air pressure has built up and the low air warning has gone off.
Pregunta 6 de 25
Why does air brake lag matter for following distance?
- It adds distance before the brakes work, so you need a bigger gap
- It only matters when the vehicle is parked
- It lets you follow more closely than a car
- It makes the brakes work instantly, so gaps can be small
Ver respuesta
Respuesta: A. It adds distance before the brakes work, so you need a bigger gap
Lag time is added to perception and reaction time, so the truck travels further before braking starts.
Pregunta 7 de 25
What does too much push rod stroke mean?
- The brake is working perfectly
- The governor is set too low
- The brake is out of adjustment
- The tank is too full
Ver respuesta
Respuesta: C. The brake is out of adjustment
Excess push rod travel means the brake is out of adjustment and will not give full braking force.
Pregunta 8 de 25
What does the parking brake control knob usually look like?
- A green toggle switch
- A blue, square lever
- A yellow, diamond-shaped push-pull knob
- A red, round push button
Ver respuesta
Respuesta: C. A yellow, diamond-shaped push-pull knob
The parking (spring) brake control is a yellow, diamond-shaped push-pull knob.
Pregunta 9 de 25
During an air brake check, what should happen when you reduce the air pressure by fanning the brakes?
- The engine should stop when pressure falls
- The spring brakes should apply before the warning comes on
- The low air warning should come on before the spring brakes apply
- Nothing should happen until the tanks are empty
Ver respuesta
Respuesta: C. The low air warning should come on before the spring brakes apply
The warning must activate before pressure falls low enough for the spring brakes to apply.
Pregunta 10 de 25
Why should you avoid fanning (pumping) air brakes?
- It wastes air and lowers the pressure in the system
- It drains fuel from the tank
- It makes the brakes far too strong
- It overheats the engine and compressor
Ver respuesta
Respuesta: A. It wastes air and lowers the pressure in the system
Each pump uses air. Fanning the brakes can drop pressure quickly.
Pregunta 11 de 25
A truck has 16 brakes and one is out of adjustment. What happens?
- The truck stops faster than before
- The air compressor stops pumping
- Nothing; one brake out of 16 does not matter
- The other brakes must do more of the work
Ver respuesta
Respuesta: D. The other brakes must do more of the work
Each brake is designed to do its share. If one is out of adjustment, the others work harder and may overheat.
Pregunta 12 de 25
Why must water be drained from air tanks?
- Water can freeze and block valves and lines
- Water makes the brakes stronger
- Water cools the engine
- Water is needed for the brakes to work
Ver respuesta
Respuesta: A. Water can freeze and block valves and lines
Water and oil collect in the tanks. In cold weather, water can freeze and stop the system working.
Pregunta 13 de 25
About how much time does air brake lag add before the brakes begin to apply?
- About four-tenths of a second
- About 4 seconds
- About 1 full minute
- No time at all
Ver respuesta
Respuesta: A. About four-tenths of a second
Air brake lag time is about 4/10 of a second.
Pregunta 14 de 25
For how long is a passed air brake knowledge test result valid in B.C.?
- For life
- Five years
- One year
- One month
Ver respuesta
Respuesta: C. One year
The air brake knowledge test result is valid for one year.
Pregunta 15 de 25
What should you check on the compressor during the air brake inspection?
- The colour and make of the compressor
- That a belt-driven compressor's belt is in good shape and tight
- The fuel level inside the compressor
- The compressor's radio and wiring connection
Ver respuesta
Respuesta: B. That a belt-driven compressor's belt is in good shape and tight
A loose or worn belt can stop the compressor from building air.
Pregunta 16 de 25
Where do you apply to take the air brake knowledge test in B.C.?
- At your trucking company
- At a police station
- At a driver licensing office
- At a weigh scale
Ver respuesta
Respuesta: C. At a driver licensing office
Apply at a driver licensing office with your ID and pay the knowledge test fee.
Pregunta 17 de 25
How is brake adjustment checked on S-cam brakes?
- By listening to the brakes while driving slowly
- By checking the tire pressure on each axle
- By measuring push rod stroke with the brakes fully applied
- By feeling how hot each drum is after a trip
Ver respuesta
Respuesta: C. By measuring push rod stroke with the brakes fully applied
Measure how far the push rod moves on a full application. Too much stroke means the brake is out of adjustment.
Pregunta 18 de 25
Is a road test required for the air brake endorsement in B.C.?
- Yes, in a tractor-trailer
- No
- Yes, but only at night
- Yes, in a bus
Ver respuesta
Respuesta: B. No
The air brake endorsement needs a knowledge test and a pre-trip inspection test, but no road test.
Pregunta 19 de 25
When air enters a brake chamber, what moves?
- A diaphragm pushes the push rod out
- The brake drum starts to spin faster
- The governor cuts out the compressor
- The tank drain valve opens
Ver respuesta
Respuesta: A. A diaphragm pushes the push rod out
Air pressure pushes the diaphragm, which pushes the rod that turns the slack adjuster.
Pregunta 20 de 25
How does a retarder help the air brakes?
- It adds extra air to the tanks while you drive
- It makes the service brakes apply faster
- It adjusts the slack adjusters automatically
- It slows you without the service brakes, so they stay cool
Ver respuesta
Respuesta: D. It slows you without the service brakes, so they stay cool
Retarders such as engine and exhaust brakes reduce the work, heat and wear on the service brakes.
Pregunta 21 de 25
What is the possible fine for brakes that are not correctly adjusted?
- Up to $20
- Up to $100
- Up to $2,000
- No fine, only a warning
Ver respuesta
Respuesta: C. Up to $2,000
Brakes not adjusted or not performing properly can bring a fine of up to $2,000.
Pregunta 22 de 25
Which part senses tank pressure and controls the compressor?
- The slack adjuster
- The governor
- The brake chamber
- The brake drum
Ver respuesta
Respuesta: B. The governor
The governor tells the compressor when to stop (cut out) and start (cut in) pumping.
Pregunta 23 de 25
On a Class 1 road test in a vehicle with air brakes, which inspection is included?
- A full engine inspection
- A tire change on the trailer
- An air brake pre-trip inspection
- A fuel economy check
Ver respuesta
Respuesta: C. An air brake pre-trip inspection
Road tests include an air brake pre-trip inspection when the vehicle has air brakes.
Pregunta 24 de 25
What connects the push rod to the brake camshaft?
- The gladhand
- The foot valve
- The slack adjuster
- The governor
Ver respuesta
Respuesta: C. The slack adjuster
The slack adjuster links the push rod to the camshaft and adds leverage.
Pregunta 25 de 25
What temperature should brake parts not go above?
- About 900 °C
- About 60 °C
- About 250 °C
- About 120 °C
Ver respuesta
Respuesta: C. About 250 °C
Brake parts reach about 120 °C in normal stops and should not exceed about 250 °C.

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