Braking Systems and Warning Devices +7British Columbia · CDL · English

All vehicles using air or vacuum brakes must have warning devices that alert the driver if the air-pressure or vacuum system fails. Every motor vehicle must have at least two separate braking systems, one of which must be mechanical (e.g., a ratchet and pawl or spring brake). If the foot (primary) brakes fail, the driver must use the emergency (mechanical) brake, which needs more time and distance to stop.

• ✓Air or vacuum brake vehicles must have a warning device for system failure
• ✓Every vehicle must have at least two separate braking systems, one mechanical
• ✓The emergency (mechanical) brake requires more time and distance to stop

Approved warning devices are required for vehicles seating more than 10 passengers, and commercial vehicles with overall or load width over 2.3 m. Move a disabled vehicle as far off the road as possible. Place warning devices about 30 m ahead and 30 m behind. When parked in the dark, at least two warning devices are required. In daylight use two red flags at least 30 cm by 30 cm or two approved daylight devices; at night use flares, fuses, reflectors and red lanterns.

• ✓Place warning devices about 30 m ahead and 30 m behind a disabled vehicle
• ✓In daylight use two red flags at least 30 cm by 30 cm or two approved daylight devices
• ✓At night at least two warning devices such as flares, fuses, reflectors or red lanterns are required

Red flashing lights are used only on emergency vehicles; blue only on police vehicles (a police vehicle has both red and blue); amber flashing lights are used on construction, towing, snow-removal, sanding, pilot cars and permitted oversize vehicles. A permit from Commercial Vehicle Safety and Enforcement is required before mounting amber flashing lights.

• ✓Red flashing lights are only for emergency vehicles; blue only for police
• ✓A permit from Commercial Vehicle Safety and Enforcement is required to mount amber flashing lights

Dangerous goods present serious hazards to handlers, the public and the environment. People handling dangerous goods have significant legal responsibilities and must be properly trained and certified. All shipping documents must be complete, correct and readily available in the cab, accompanying the shipment. Any incident related to a dangerous goods cargo must be reported immediately.

• ✓Handlers of dangerous goods must be properly trained and certified
• ✓Shipping documents must be complete, correct and readily available in the cab
• ✓Documents must accompany the dangerous goods shipment
• ✓Report any dangerous goods incident immediately

Livestock can move around in a trailer, making turns difficult and risking collisions or animal injury. With less than a full load, use false bulkheads to keep animals bunched. Reduce speed on curves because animals lean, shifting the centre of gravity and risking rollover. Hanging meat sways and has a high centre of gravity — secure suspended items so they cannot shift or sway, reduce speed on sharp curves, and take extra care on on-ramps and off-ramps.

• ✓Use false bulkheads to bunch livestock when less than a full load
• ✓Reduce speed on curves — leaning animals shift the centre of gravity
• ✓Secure hanging meat so it cannot shift or sway
• ✓Take extra care on ramps with high centre-of-gravity loads

Liquid or dry bulk tank loads often have a high centre of gravity, increasing rollover danger. These loads shift, and if not baffled they surge forward, backward and side to side. Reduce speed on curves and sharp turns and be especially careful on stops and starts.

• ✓Bulk tank loads have a high centre of gravity increasing rollover risk
• ✓Unbaffled liquid loads surge in all directions
• ✓Reduce speed on curves and sharp turns
• ✓Be especially careful on stops and starts

Combination vehicles use hitches such as the pintle hitch and equipment like pole trailers. Proper coupling and uncoupling is essential to prevent trailer separation. Understand whipping, rollovers and parking of trailers.

• ✓Use the correct hitch (e.g., pintle hitch) properly rated for the load
• ✓Couple and secure trailers correctly to prevent separation
• ✓Understand whipping and rollover risks when towing

Trailers can whip and roll over, especially when improperly loaded or driven too fast in turns. Park trailers safely and chock as needed. Recreational and semi-trailers have specific licence requirements.

• ✓Reduce speed in curves to prevent trailer rollover
• ✓Load trailers to keep the centre of gravity low and balanced
• ✓Park and secure trailers safely, using chocks where needed

Carbon monoxide is odourless, colourless, tasteless and in every vehicle's exhaust. It can seep into the driving compartment causing dizziness, drowsiness, unconsciousness and death. Check the exhaust system, never run an engine in a closed garage, and don't follow too closely. If you feel dizzy or drowsy, pull over and get fresh air.

• ✓Carbon monoxide is odourless, colourless and tasteless and present in all exhaust
• ✓Never run your engine in a closed garage
• ✓If you feel dizzy or drowsy, pull over, stop, and get fresh air
• ✓Check the exhaust system to ensure fumes aren't entering the cab

Seatbelts save lives and reduce the risk of striking the interior, colliding with passengers, or ejection. Correct use of a lap and shoulder belt reduces the likelihood of death by about 50 per cent. You cannot hold yourself back in a collision. Some drivers who get in and out frequently may be exempt at 40 km/h or less.

• ✓Place the lap belt low over the pelvis, not the stomach, and keep it snug
• ✓Ensure the shoulder strap is snug across the chest; never under the arm or behind the back
• ✓Correct lap-and-shoulder belt use reduces death likelihood by about 50 per cent
• ✓Some frequent in-and-out drivers may be exempt when driving at 40 km/h or less

Most large trucks lack airbags and head restraints. Even with airbags you must wear a seatbelt, as airbags can injure unbelted occupants. Keep at least 25 cm between breastbone and the steering wheel airbag. Adjust head restraints so the top is at least as high as the top of your head and less than 10 cm from the back of your head.

• ✓Wear a seatbelt even if the vehicle has airbags
• ✓Keep at least 25 cm (10 in) between breastbone and steering wheel airbag
• ✓Head restraint top should be at least as high as the top of your head and less than 10 cm from the back of your head

All B.C. drivers are prohibited from using hand-held electronic devices while driving, including calls, texting, e-mail, gaming, and manually programming GPS. GLP drivers are also restricted from hands-free devices. Non-GLP (including commercial) drivers may use hands-free devices and single-button-activated devices in a fixed location, plus two-way radios and mobile data terminals. Restrictions don't apply to calling 9-1-1.

• ✓Hand-held electronic devices are prohibited while driving for all B.C. drivers
• ✓GLP drivers are also restricted from hands-free devices
• ✓Non-GLP drivers may use hands-free devices, two-way radios and mobile data terminals
• ✓Restrictions don't apply when calling 9-1-1 to report an emergency

Alcohol, marijuana, illicit drugs and some prescription/stay-awake drugs impair driving. Penalties apply under the Motor Vehicle Act and Criminal Code. You may be prohibited if a police officer considers your ability affected even without BAC over .08 or BDC of 2 nanograms THC. Criminal Code penalties escalate for repeat offences and include lifetime prohibitions and jail. Police can impound vehicles for various offences.

• ✓Penalties apply for BAC over .08, BDC of 2 nanograms+ THC, or refusing to provide a sample
• ✓A police officer can prohibit you even without reaching the legal BAC/BDC limits
• ✓Police can impound a vehicle for seven days (up to 30/60 for repeat offenders) for driving unlicensed, suspended, excessive speeding (40 km/h+ over), or stunt driving
• ✓Vehicle owners are responsible for ensuring only licensed drivers use their vehicles

Antihistamines, sedatives, tranquilizers and some cold remedies cause drowsiness; read labels and check with a pharmacist. There's no safe substitute for proper rest; stay-awake tablets don't reduce mental fatigue. Follow National Safety Code hours of service. Emotions like road rage or distraction impair focus.

• ✓Read medication labels for side effects that impair driving and consult a pharmacist/physician
• ✓There's no safe substitute for proper rest; pull over and sleep if fatigued
• ✓Follow National Safety Code hours of service regulations and get enough sleep every 24 hours

To prevent fires: never start a vehicle with a fuel leak (repair and clean up spills properly); shut off engines when refuelling; keep the fuel nozzle in contact with the filler pipe to ground the connection; connect the ground strap if equipped. Recommended safety equipment includes flags/flares, a fire extinguisher, and a first aid kit.

• ✓Never start a vehicle with a fuel leak; repair it and clean up the spill
• ✓Shut off engines when refuelling
• ✓Keep the fuel nozzle in contact with the filler pipe to ground the connection
• ✓Carry recommended safety equipment: flares, fire extinguisher, and first aid kit

Several dangerous misconceptions exist. Checking adjustment from the cab via pressure drop doesn't work because modern reservoirs are large and gauges too coarse. A 90-degree slack adjuster angle depends more on pushrod length than adjustment. A clockwise turn doesn't always set up manual slack adjusters — direction depends on orientation and varies between tandem axles. There is no reliable substitute for physically checking brake adjustment.

• ✓Brake adjustment cannot be reliably checked from the cab by watching for pressure drop
• ✓A 90-degree slack adjuster angle is not a reliable indicator of correct adjustment
• ✓Direction to set up a manual slack adjuster can be clockwise or counter-clockwise depending on orientation
• ✓There's no reliable substitute for physically checking brake adjustment

Test the brakes on your school bus every day and never operate it unless the brakes are safe. Never transport passengers on a school bus that is defective in any way — keeping passengers safe is your first responsibility. Ensure all passengers are off and the engine is off before refuelling.

• ✓Test school bus brakes every day
• ✓Never operate a school bus with unsafe brakes or any defect
• ✓Ensure all passengers are off and engine is off before refuelling

Before opening doors, ensure the vehicle is fully stopped, there are at least three metres of road on the left side, other drivers can see the bus from at least 60 metres in both directions, and passengers enter/leave from the right side only. School buses have alternating flashing red lights, swing-out stop signs and may have amber lights. Use flashing red lights whenever passengers are crossing the road. All drivers must stop when a school bus displays flashing red lights. New buses may have a crossing control arm. Turn off flashing lights and draw in the stop sign once passengers are safe.

• ✓Ensure at least three metres of road on the left before loading/unloading
• ✓Other drivers must be able to see the bus from at least 60 metres each direction
• ✓Passengers enter and leave from the right side only
• ✓All drivers must stop when a school bus displays flashing red lights

Requirements for operating a bus also apply to school buses, which must comply with all parts of the MVAR relating to school buses. If a mechanical inspector or peace officer finds a school bus unfit, you cannot operate it as a school bus until the defect is fixed. Rental buses temporarily replacing a school bus must comply with school bus regulations, and you must notify Commercial Vehicle Safety and Enforcement of the change as soon as possible.

• ✓School buses must comply with all school bus provisions of the MVAR
• ✓An unfit school bus cannot be operated until defects are fixed
• ✓Rental replacement buses must comply and CVSE must be notified

All school buses must display two 'School Bus' signs with letters at least 20 cm high, black on a yellow background, mounted at the front and rear (rear sign immediately above or below the rear window). Every new school bus must have two sets of rear-view mirrors on each side, a mirror giving a good view of the entrance door, and a convex front mirror to see the roadway immediately in front. Mirrors must be properly adjusted.

• ✓Two 'School Bus' signs required, letters at least 20 cm high, black on yellow
• ✓Signs mounted at front and rear, rear sign above or below the rear window
• ✓New school buses need side rear-view mirrors, an entrance door mirror and a convex front mirror

Passengers are not allowed to stand on a school bus. Ensure all passengers are seated before moving the bus. The floor of a school bus must be washed with a disinfectant solution at least once a week.

• ✓Passengers may not stand on a school bus
• ✓Ensure all passengers are seated before moving
• ✓Wash the school bus floor with disinfectant at least once a week

Air brakes use compressed air to apply braking force, offering advantages for heavy vehicles. Compressed air stores energy that is used to actuate the brakes through force-multiplying components.

• ✓Air brakes use compressed air to actuate braking force
• ✓Compressed air stores energy released when brakes are applied
• ✓Air brakes are suited to heavy vehicles due to their force-multiplying capacity

Air brake chambers convert air pressure into mechanical force. Leverage and air pressure multiply braking force. Long stroke and regular stroke chambers differ in adjustment limits.

• ✓Air brake chambers convert air pressure into mechanical braking force
• ✓Leverage and air pressure multiply braking force through the slack adjuster
• ✓Long stroke and regular stroke chambers have different maximum stroke limits

The compressor supplies compressed air to the system through intake and compression strokes. The governor controls when the compressor loads (cut-in) and unloads (cut-out) to maintain system pressure.

• ✓The compressor supplies compressed air via intake and compression strokes
• ✓The governor controls compressor cut-in and cut-out pressures
• ✓The governor maintains reservoir pressure within a set range

When brakes are applied, air flows to the brake chambers to apply braking force; when released, air is exhausted from the chambers. Understanding the flow is essential for diagnosing brake operation.

• ✓Applying the brakes sends air to the chambers to create braking force
• ✓Releasing the brakes exhausts air from the chambers
• ✓Air flow direction determines whether brakes apply or release

Dual air brake systems have separate primary and secondary circuits so a failure in one still allows braking with the other. Components include supply, primary and secondary reservoirs and a one-way check valve.

• ✓Dual systems have separate primary and secondary circuits for redundancy
• ✓A one-way check valve protects reservoirs during a leak or failure
• ✓A failure in one circuit still allows braking with the other circuit

Reservoir pressure gauges display system pressure, and a low-air warning device alerts the driver when pressure falls below a safe level (typically about 55 psi).

• ✓A low-air warning device activates when pressure drops to about 55 psi
• ✓Reservoir pressure gauges show primary and secondary system pressure
• ✓Do not drive if the low-air warning is active

Air brakes use compressed air to multiply the driver's braking effort, allowing heavy vehicles to be stopped effectively. Compressed air is air squeezed into a smaller space, storing energy.

• ✓Air brakes use compressed air to multiply force and stop heavy vehicles
• ✓Compressed air stores energy that is used to apply the brakes

The air brake chamber converts air pressure into mechanical force, and leverage through the slack adjuster and cam multiplies that force. Long stroke and regular stroke chambers differ in effective travel.

• ✓The brake chamber converts air pressure into mechanical force to apply the brakes
• ✓Long stroke and regular stroke chambers have different maximum allowable pushrod travel

S-cam foundation brakes use the rotation of an S-shaped cam to force the brake shoes against the drum. The slack adjuster transfers chamber force to the cam.

• ✓The S-cam rotates to push brake shoes against the drum when brakes are applied
• ✓The slack adjuster connects the chamber pushrod to the S-cam and can adjust brake clearance

The compressor builds air pressure through intake and compression strokes, and the governor controls when the compressor loads and unloads to maintain system pressure within a set range.

• ✓The compressor builds air pressure and the governor controls cut-in and cut-out pressures
• ✓The governor unloads the compressor at cut-out pressure and loads it at cut-in pressure

Reservoirs store compressed air for braking, and the foot valve (application valve) controls how much air is delivered to the brakes based on pedal pressure.

• ✓Reservoirs store compressed air to supply the brake system
• ✓The foot valve meters air to the brakes in proportion to how far the pedal is pressed

When the brakes are applied, air flows to the brake chambers to push the shoes against the drums; when released, air is exhausted and springs return the shoes. This is the basic operating cycle.

• ✓Applying the brakes sends air to the chambers to push shoes against drums
• ✓Releasing the brakes exhausts air and allows return springs to retract the shoes

Dual air brake systems have separate primary and secondary circuits fed from a supply reservoir, providing redundancy so braking remains if one circuit fails. A one-way check valve prevents air loss.

• ✓A dual air brake system has separate primary and secondary circuits for redundancy
• ✓A one-way check valve prevents loss of air from one circuit if another fails

Reservoir pressure gauges show system air pressure, and a low-air warning device alerts the driver when pressure drops to an unsafe level. These are essential safety indicators.

• ✓Reservoir pressure gauges display primary and secondary system pressures
• ✓The low-air warning device must activate when pressure drops to about 55 psi or below

Spring parking brakes use powerful springs to apply the brakes when air pressure is released, providing a fail-safe park and emergency braking function.

• ✓Spring parking brakes apply automatically when air pressure is released or lost
• ✓Air pressure holds the spring parking brakes off during normal driving

Tractor-trailer air brake systems include relay emergency valves or spring parking brakes on the trailer, and operate in charging, applying and emergency (dynamited) states. Proper charging is required before moving.

• ✓The trailer must be fully charged with air before the trailer brakes will release
• ✓If the trailer air supply is lost, the trailer emergency brakes apply (dynamite)

The tractor protection system, including the trailer air supply valve and hand valve, protects the tractor's air supply if a trailer breakaway or major air leak occurs.

• ✓The tractor protection valve protects the tractor air supply during a trailer breakaway or major leak
• ✓The trailer air supply valve controls air to the trailer and applies trailer brakes when closed

The quick release valve speeds up the release of air from the brake chambers, and the relay valve speeds application and release of the rear brakes by using a nearby air source.

• ✓The quick release valve speeds exhausting of air to release the brakes faster
• ✓The relay valve speeds up brake application and release on rear axles

Compounding occurs when the spring parking brake and service brake are applied simultaneously, adding forces that can damage brake components. Drivers must avoid this condition.

• ✓Avoid applying the service brake while the spring parking brake is applied to prevent compounding
• ✓Compounding of brake forces can damage the brake components

Spring parking brakes can be manually caged (released) using the release bolt when there is no air pressure, allowing the vehicle to be moved for repairs.

• ✓Spring parking brakes can be manually caged/released using the release bolt
• ✓Manually releasing spring brakes removes the parking and emergency braking capability

All B.C. drivers are prohibited from using hand-held electronic devices while driving, including holding phones, texting/emailing, gaming, and manually programming a GPS. GLP drivers are also restricted from hands-free devices. Non-GLP, including commercial drivers, may use hands-free devices and single-button-activated devices in a fixed location, plus pre-programmed/voice GPS, two-way radios and mobile data terminals. Restrictions don't apply to calling 9-1-1.

• ✓All drivers are prohibited from using hand-held electronic devices while driving
• ✓Non-GLP commercial drivers may use hands-free and single-button devices in a fixed location
• ✓Restrictions do not apply when calling 9-1-1 to report an emergency

Carbon monoxide is odourless, colourless, tasteless and difficult to detect, and is in every vehicle's exhaust. It can make you dizzy, drowsy or unconscious and can kill. Check the exhaust system so fumes don't enter the cab. Never run an engine in a closed garage. Don't follow too closely and keep a safe distance when stopped. If you feel dizzy or drowsy, pull over, stop, and get fresh air.

• ✓Never run your engine in a closed garage
• ✓Check the exhaust system to ensure fumes don't enter the driver's compartment
• ✓If you feel dizzy or drowsy, pull over, stop and get fresh air

Seatbelts save lives and reduce ejection and injury risk. You cannot hold yourself back in a crash regardless of strength. Some frequent-stop workers may be exempt when driving at 40 km/h or less. Adjust correctly: place the lap belt low over the pelvis (snug, not over the stomach), keep the shoulder strap snug across the chest, never under the arm or behind the back, and remove all slack.

• ✓Place the lap belt low over the pelvis, snug, not over the stomach
• ✓Keep the shoulder strap snug across the chest, never under the arm or behind the back
• ✓Some frequent-stop drivers may be exempt only at 40 km/h or less

Most large trucks aren't equipped with airbags and head restraints. Even with airbags, wear your seatbelt, as airbags can injure unbelted occupants. Allow at least 25 cm between your breastbone and the airbag in the steering wheel. Adjust head restraints so the top is at least as high as the top of your head and less than 10 cm from the back of your head to prevent neck injury.

• ✓Even with airbags, always wear your seatbelt
• ✓Allow at least 25 cm between your breastbone and the steering wheel airbag
• ✓Set the head restraint top at least as high as the top of your head and within 10 cm of your head