Module 8: Automatic Slack Adjusters +7Alberta · CDL · English

On all automatic slack adjusters, the brake is being tightened correctly if the wrench turns the s-cam shaft in the same direction as brake application - the same indicators used for manual slack adjusters. Adjusting automatic slack adjusters is not a normal procedure; it is only to get the vehicle safely to a repair facility. Using it as regular maintenance will damage the automatic adjusters.

• ✓On all automatic slack adjusters, correct tightening turns the s-cam shaft in the direction of brake application
• ✓Adjusting automatic slack adjusters is an emergency measure only; regular use damages them

Vehicles manufactured with automatic slack adjusters cannot be retrofitted with manual slack adjusters. There are various manufacturers of automatic slack adjusters, and each may offer more than one model.

• ✓Vehicles built with automatic slack adjusters cannot be changed to manual slack adjusters
• ✓Different manufacturers each may have several models of automatic slack adjuster

Arvin Meritor slack adjusters are recognized by the square adjusting head on the end of the self-adjusting mechanism. It is the only automatic slack adjuster that uses brake application stroke for adjustments (others measure lining-to-drum clearance), taking up excess slack on the return stroke. Emergency adjustment uses a 5/16 inch open end wrench, tightening to the LEFT (counterclockwise) - the only one that tightens left. The pawl (round button on side) must be lifted to back off the brake.

• ✓Recognized by the square adjusting head on the self-adjusting mechanism
• ✓Uses application stroke for adjustment; takes up excess slack on the return stroke
• ✓Emergency adjustment: 5/16 inch wrench, tighten counterclockwise (left) - the only one to tighten left
• ✓Lift the pawl (round button) to back off the brake

Automatic slack adjusters are activated by full brake applications, sometimes called a 'six pack' (six full applications), though only the first few applications have adjusting value. Normal service applications and spring park brake applications (about half of a full service application) do not properly trigger automatic adjustment. To activate properly: keep air pressure in the normal range (above 100 PSI / 690 kPa), press the foot valve firmly to the floor, and account for brake lag with one-second intervals between applications and releases. Do not excessively fan or pump the pedal.

• ✓Keep air pressure above 100 PSI (690 kPa) when activating automatic adjusters
• ✓Press the foot valve firmly to the floor with one-second intervals to account for brake lag
• ✓Spring park brake applications (~half a full service application) do NOT properly trigger automatic adjustment
• ✓Only the first few of the 'six pack' applications have adjusting value; do not excessively fan or pump

Disc brake rotors can be hard to see, with cracks hidden behind brake pads, backing plates, or callipers. However, some part of the rotor is generally visible, so inspecting rotors often means any cracks will eventually become visible. Rotors should be checked during inspections and throughout the work shift.

• ✓Inspect disc rotors frequently since cracks may hide behind pads, backing plates, or callipers
• ✓Some part of a rotor is generally visible; regular checks reveal developing cracks

Bendix adjusters have the Bendix name on the side, measure lining-to-drum clearance, and gather excess slack on the application stroke. Crewson adjusters have a decal and triangular pointer from the two clevis pins, measure shoe-to-drum clearance, and gather excess slack on the return stroke. Haldex is the only automatic adjuster with a single clevis pin (like a manual), using an anchor bracket attached to axle components; it takes up slack on the release stroke. Gunite adjusters are recognized by two tabs cast on the s-cam shaft end of the housing, gathering slack on the application stroke. All four use a 7/16 inch wrench turned clockwise to tighten for emergency adjustment.

• ✓Bendix, Crewson, Haldex and Gunite all use a 7/16 inch wrench turned clockwise to tighten
• ✓Haldex is the only automatic slack adjuster with a single clevis pin, similar to a manual adjuster
• ✓All of these measure lining/shoe-to-drum clearance (unlike Arvin Meritor)
• ✓Gunite is recognized by two tabs cast on the s-cam shaft end of the housing

Making a single full brake application whenever the vehicle is stopped with drums cool and park brakes released is a good habit. The air loss from a full application is not significant enough to reduce air pressure from normal levels. This habit is comparable to regularly scanning mirrors and engine gauges.

• ✓Make a single full service application when stopped with drums cool and park brakes released
• ✓A single full application does not significantly reduce normal air pressure

To test the tractor protection system, leave the engine off with the key in the run position and confirm the wheels are chocked. Push the trailer air supply valve (red button); the park control valve (yellow button) should be pulled. Disconnect both air lines to the trailer. Confirm the low air pressure warning comes on by 60 PSI (414 kPa). Confirm the trailer air supply valve (red button) pops out at 40-60 PSI (276-414 kPa) or higher. Apply and hold the foot or hand valve; no air should leak from the open trailer service line.

• ✓Engine must be off with key in run position and wheels chocked
• ✓Low air pressure warning must come on by 60 PSI (414 kPa)
• ✓Trailer air supply valve (red button) must pop out at 40-60 PSI (276-414 kPa) or higher
• ✓No air should leak from the open trailer service line when foot or hand valve is applied

When uncoupling air lines, hold a hand over the supply coupler to protect from air pressure release and debris. When coupling, inspect glad hand couplers before connecting, connect them properly, and confirm correct connection. Ensure air lines are suspended and won't catch as the trailer turns.

• ✓Hold a hand over the supply coupler when uncoupling to protect from air pressure release and debris
• ✓Inspect glad hand couplers before connecting and confirm they are properly connected

To activate automatic slack adjuster adjustment, restart the engine to maintain air pressure and apply two full service brake applications in the normal operating range, allowing one second intervals to account for brake lag. Confirm proper brake adjustment by pulling the slack adjusters of both brakes on one axle.

• ✓Apply two full service brake applications with one-second intervals to trigger automatic slack adjuster adjustment
• ✓Confirm correct adjustment by pulling the slack adjusters of both brakes on one axle (rear trailer axle is easiest)

Each task on the Practical Test form has a weight of 5%, 10% or 15%. Errors totalling 25% or more result in test failure, as 80% is required to pass. Only the brake adjustment of one axle needs to be checked. The 15-minute time limit applies, and failure to complete requires a retest on another day.

• ✓80% is required to pass; errors totalling 25% or more result in failure
• ✓Each task is weighted 5%, 10% or 15%; only one axle's brake adjustment is checked

Students must observe and practise adjusting s-cam drum brakes, adjusting the brakes twice each. They must understand s-cam shaft rotation, how to turn the adjusting bolt correctly, how to recognize proper stroke when backed off, and that the spring loaded lock sleeve is in place.

• ✓Each student must adjust the brakes twice and observe other students
• ✓Understand s-cam shaft rotation, adjusting bolt operation, proper stroke, and spring loaded lock sleeve placement

Effective March 1, 2019, anyone seeking a Class 1 or Class 2 licence must complete a Mandatory Entry-Level Training (MELT) program. Successful completion is a prerequisite before taking the Class 1 or Class 2 knowledge test.

• ✓MELT is mandatory for Class 1 and Class 2 licences since March 1, 2019
• ✓MELT completion is a prerequisite to writing the Class 1 or Class 2 knowledge test
• ✓Most Class 1 and Class 2 knowledge test questions come from the MELT curriculum

The knowledge test is based on this guide and the Cars and Light Trucks guide. It has 30 multiple choice questions covering safe driving, laws and road signs. Class 1 applicants may be asked questions from any chapter since they can drive multiple vehicle types.

• ✓Test is 30 multiple choice questions
• ✓Minimum 25 correct out of 30 needed to pass
• ✓Test stops and a fail is recorded after six incorrect answers
• ✓Class 1 applicants may be asked questions from any chapter of the guide

A vision assessment is required before upgrading. If minimum vision standards are not met, a Vision Referral form must be completed by an optometrist or ophthalmologist. Class 1, 2 and 3 applicants must complete a pre-trip inspection in addition to the road test, communicating and demonstrating each item to the examiner.

• ✓Vision assessment required before upgrading; bring corrective lenses
• ✓Class 1, 2 and 3 applicants must perform a pre-trip inspection before the road test
• ✓Must demonstrate couple/uncouple procedures for Class 1 vehicles
• ✓Must inspect the air brake system on air brake equipped units
• ✓You may not refer to notes during the pre-trip inspection
• ✓If the pre-trip is not successfully completed, the road test will not proceed

An applicant holding a Graduated Driver Licence may not take a road test for a classification higher than Class 5. A road test will not be conducted in a vehicle required to display dangerous goods placards.

• ✓GDL holders cannot take a road test higher than Class 5
• ✓Road tests are not done in vehicles required to display dangerous goods placards
• ✓Each pre-trip inspection and road test has a set time limit

The distance a commercial vehicle needs to stop is affected by brake condition, traction, weight and speed.

• ✓Brake condition: all brakes must share the task equally or others generate more friction and take longer
• ✓Traction depends on road condition, tire contact, tire condition/inflation and gross vehicle weight
• ✓There is the most traction just before all wheels lock up and less when wheels are skidding
• ✓When weight is doubled, force needed doubles and it takes about twice as long to stop
• ✓Doubling speed requires four times the braking force
• ✓Doubling both speed and weight increases force required by eight times

Total stopping distance is measured from when a driver realizes the need to apply brakes until full stop, and is affected by four time components each with a corresponding distance.

• ✓Average perception time is about three-quarters of a second
• ✓Normal driver reaction time is about three-quarters of a second
• ✓Reaction time slows if the driver is tired or has been drinking alcohol or using drugs
• ✓Lag time (air brake response) takes about 4/10 of a second
• ✓Total stopping distance = perception distance + reaction distance + lag time distance + braking distance

The distance a commercial vehicle needs to stop is affected by brake condition, traction, weight (GVW) and speed. Poorly maintained brakes force remaining brakes to work harder, lengthening stopping distance.

• ✓Four factors affecting stopping: brake condition, traction, weight and speed
• ✓There is the most traction just before the wheels lock up and less traction when wheels skid
• ✓When weight is doubled, force needed doubles and stopping takes about twice as long
• ✓Doubling speed requires four times the braking force; doubling both speed and weight requires eight times the force

Total stopping distance is measured from when a driver realizes the need to brake until the vehicle fully stops. It is the sum of perception distance, reaction distance, lag time distance and braking distance.

• ✓Perception time averages about three-quarters of a second
• ✓Driver reaction time is about three-quarters of a second and is slower if tired or impaired by alcohol/drugs
• ✓Air brake lag time is about 4/10 of a second because compressed air takes time to flow and apply brakes
• ✓Total stopping distance = perception + reaction + lag time + braking distance

Apply the brakes using even pressure and ease off as the vehicle slows. Do not pump air brakes because this causes loss of air pressure, especially dangerous on long downhill grades.

• ✓Apply even pressure, ease off as vehicle slows, release just before stopping to avoid jerk, then reapply to hold
• ✓Do not pump air brakes as this results in a loss of air pressure
• ✓Downshift before the top of a hill and use engine compression to control speed on steep grades
• ✓Test brakes before going down a hill and do not proceed if there is abnormal air pressure loss

Stop safely if a low air pressure warning occurs and restore pressure before continuing. Excessive use of the trailer hand valve causes unbalanced braking that can cause jackknifing.

• ✓If there is a low air pressure warning, stop as soon as possible in a safe place and increase pressure before continuing
• ✓Overuse of the trailer hand valve on steep hills can cause trailer brakes to fail and unbalanced braking that leads to jackknifing
• ✓Improperly adjusted brakes make some brakes work harder and can cause a skid
• ✓A driver must not pull any trailer over 2,300 kg not equipped with driver-controlled brakes

To stop a moving vehicle a driver must See a hazard, Think and decide to stop, and Do by placing foot on the brake pedal until the vehicle stops. Heavy commercial vehicles take more time and distance to stop than smaller vehicles.

• ✓The three actions are See, Think, and Do
• ✓Heavy commercial vehicles need more braking force to overcome weight and forward motion

The slope or grade of the road affects stopping distance because of gravity.

• ✓A vehicle travelling downhill needs a longer stopping distance than on a level surface
• ✓A vehicle travelling uphill stops in a shorter distance than on a level surface

To stop a moving vehicle a driver must See a hazard, Think and decide to stop, then Do by placing foot on the brake pedal until the vehicle stops. Heavy commercial vehicles take more time and distance to stop than smaller vehicles.

• ✓Three actions to stop: See a hazard, Think to decide to stop, Do by applying brakes
• ✓Heavy commercial vehicles need more braking force to overcome weight and forward motion

Traction is the friction between the tire and the road surface. More traction means less time and distance to stop.

• ✓Traction depends on road condition, tire contact with the road, tire condition/inflation pressure, and gross vehicle weight
• ✓There is the most traction just before all wheels lock up and less when skidding

Braking time depends on brake application force, condition of linings and drums, tire traction, and vehicle weight and speed. Road slope also affects stopping distance.

• ✓Braking time depends on brake force applied, condition of linings and drums, tire traction, and vehicle weight and speed
• ✓A vehicle travelling downhill needs a longer stopping distance due to gravity
• ✓A vehicle travelling uphill stops in a shorter distance due to the grade

Driving while exhausted makes you a road hazard. Drowsy driving is as dangerous as impaired driving because it slows reaction time, decreases awareness and impairs judgment like alcohol or drugs.

• ✓Drowsy driving is as dangerous as impaired driving
• ✓Fatigue slows reaction time, decreases awareness and impairs judgment
• ✓Lack of sleep is one of the most common causes of drowsy driving

Recognize fatigue warning signs: yawning; inability to keep eyes focused and head up; wandering, disconnected thoughts; driving the past few kilometres without remembering them; drifting between lanes, tailgating or missing traffic signs; and noticing a vehicle in the rear view mirror that seemed to appear out of nowhere.

• ✓Warning signs include yawning, drifting between lanes, tailgating and missing traffic signs
• ✓Driving without remembering the past few kilometres is a key fatigue sign
• ✓Missing time or being surprised by nearby vehicles indicates dangerous fatigue

Short-term measures (radio, open window, coffee, gum, eating) only help briefly. To prevent fatigue: know your biological clock and avoid down times; stop if sleepy; get plenty of sleep before long trips; avoid working all day then driving all night; schedule breaks; take a mid-afternoon nap; and travel with an awake passenger.

• ✓Schedule a break every two hours or every 160 km to stretch and get fresh air
• ✓Take a mid-afternoon break with a 20-40 minute nap
• ✓Get plenty of sleep before a long trip and stop if you become sleepy
• ✓Avoid working all day and driving all night — stay overnight rather than driving straight through

Short-term measures like radio, fresh air, coffee, gum or eating only help briefly. To prevent fatigue: be aware of your biological clock and avoid driving during down times, stop when sleepy, get plenty of sleep before a long trip, avoid working all day then driving all night, schedule breaks, take a mid-afternoon nap, and travel with an alert passenger.

• ✓Schedule a break every two hours or every 160 km
• ✓Take a mid-afternoon 20-40 minute nap
• ✓Get plenty of sleep before a long trip and stop if you become sleepy
• ✓Avoid working all day and then driving all night; stay overnight instead

Contributing factors to fatigue include driving alone, driving long distances without breaks, driving through the night or at times the driver normally sleeps, taking sleep-inducing medication, and drinking alcohol. Those most at risk are shift workers, commercial drivers, people with untreated sleep disorders, teenagers and young adults.

• ✓Driving alone, long distances without rest, and driving at night increase fatigue risk
• ✓Sleep-inducing medication and alcohol contribute to driver fatigue
• ✓Shift workers, commercial drivers, people with untreated sleep disorders, teenagers and young adults are most at risk

Most fatigue-related collisions happen between 1-4 p.m. and early morning between 2-6 a.m. They typically occur at higher speeds and can result in running off the road or head-on collisions with vehicles or stationary objects.

• ✓Most fatigue collisions occur between 1-4 p.m. and 2-6 a.m.
• ✓Fatigue-related collisions typically occur at higher speeds
• ✓These collisions often involve running off the road or head-on impacts

Lack of sleep is the most common cause of drowsy driving. Other contributing factors include driving alone, driving long distances without rest breaks, and driving through the night. Medication and alcohol increase fatigue. Those most at risk include shift workers, commercial drivers, people with untreated sleep disorders, teenagers and young adults.

• ✓Lack of sleep is the most common cause of drowsy driving
• ✓Driving alone, long distances without breaks, and night driving contribute to fatigue
• ✓Shift workers, commercial drivers, people with sleep disorders, teens and young adults are most at risk

During the practical test students perform an air brake pre-trip inspection and a brake adjustment on a tractor-trailer unit. Each task is weighted 5%, 10% or 15%. Errors totalling 25% or more result in a test failure, as 80% is required to pass. The test has a fifteen minute time limit and only the brake adjustment of one axle needs to be checked.

• ✓Each task is weighted 5%, 10% or 15%
• ✓Errors totalling 25% or more result in failure; 80% is required to pass
• ✓The practical test time limit is fifteen minutes; exceeding it discontinues the test
• ✓Only the brake adjustment of one axle needs to be checked during the practical test

Each student must be tested privately without other students present, at a ratio of one instructor to one student. Students must complete the operations on the Air Brake Practical Test form without assistance and without using the form as a checklist. Students who fail must retake the test on another day.

• ✓The practical test must be conducted one instructor to one student with no other students present
• ✓Students cannot use the practical test form during the test
• ✓Unsuccessful students must retake the test on another day

A daily vehicle inspection identifies problems and defects before highway operation. It is part of the carrier's written maintenance program. A completed trip inspection and report are valid for a maximum of 24 hours.

• ✓Trip inspections identify defects before highway operation
• ✓An inspection and report are valid for a maximum of 24 hours
• ✓Drivers may not drive unless an inspection was done within the previous 24 hours
• ✓Driver must carry the schedule and report in the vehicle

Drivers must record defects immediately after inspection or upon discovery. Minor and major defects must be reported to the carrier immediately. A driver may continue with a minor defect but must never operate a vehicle with a major defect.

• ✓Record defects immediately after inspection or upon discovery
• ✓Report minor and major defects to the carrier immediately
• ✓May continue to drive with a listed minor defect if recorded and reported
• ✓No person shall drive a vehicle with a major defect present

Steering axle tires must have tread depth not less than 3.2 mm; other axle tires not less than 1.6 mm. Tires must be properly inflated with no bulges, cuts or uneven wear. Wheel rims must have no cracks, and fasteners must be secure.

• ✓Steering axle tire tread depth not less than 3.2 mm
• ✓Drive and trailer axle tire tread depth not less than 1.6 mm
• ✓Tires must have no bulges, sidewall separation, cuts or uneven wear
• ✓Dual tires must not touch and nothing trapped between them
• ✓Wheel fasteners must be secure, not missing, broken or loose

For air brake vehicles, check that the air compressor is securely mounted; inspect lines, fittings, hoses and couplers; check brake chambers for condition and security; check slack adjuster angle and push rod travel; and ensure air lines have no leaks or damage.

• ✓Air compressor must be securely mounted
• ✓Check slack adjuster angle, push rod travel and mechanical wear
• ✓Brake chambers must be secure with no cracks, corrosion or holes
• ✓Air lines must have no leaks, kinks, cuts, abrasions or cracks
• ✓Use a pry bar or pull manually to check slack adjuster travel

During inspection the fifth wheel coupler bolt must be secure, the slider locked, the plate flush to the apron with no daylight, locking jaws closed around the kingpin, and the kingpin enclosed and undamaged.

• ✓Fifth wheel coupler bolt secure and slider locked
• ✓Plate flush to the apron with no daylight visible between them
• ✓Fifth wheel locking jaws closed and kingpin enclosed
• ✓Kingpin and pintle hitch eyehook not worn, damaged, cracked or broken

The trip air brake inspection includes a visual check, tractor protection system test, park control valve test, supply circuit test, air system leak test, and service brake response test, each with specific pressure thresholds.

• ✓Trailer air supply valve should pop out at 40-60 PSI (276-414 kPa) or higher
• ✓Low air pressure warning should come on by 60 PSI (414 kPa)
• ✓Park control valve should pop out at 20-45 PSI (138-311 kPa)
• ✓Governor cut-out at 120-135 PSI (828-931 kPa)
• ✓Cut-in must be 20-25 PSI less than cut-out pressure
• ✓Compressor build-up: 50 to 90 PSI within 3 minutes

With engine off after building pressure, apply and firmly hold a full service brake application for 2 minutes. Maximum allowable loss is 4 PSI (28 kPa) for power units plus an additional 2 PSI (14 kPa) per trailer after the system stabilizes.

• ✓Hold full service brake application for 2 minutes with engine off
• ✓Maximum 4 PSI (28 kPa) loss for power units
• ✓Add 2 PSI (14 kPa) allowable loss per trailer
• ✓Measure loss after the system stabilizes

Daily vehicle inspections identify problems and defects before highway operation. The process is part of a carrier's legal maintenance program and serves as communication between drivers, carrier and maintenance.

• ✓An inspection and report are valid for a maximum of 24 hours
• ✓The driver must carry the schedule and report in the vehicle and produce them on demand of a peace officer
• ✓Reports are completed immediately following an inspection
• ✓Inspection prevents operation of a vehicle with conditions likely to cause or worsen a collision

The weight thresholds for required trip inspection reports differ between provincially and federally regulated carriers.

• ✓Provincial carriers: trucks registered 11,794 kg and greater, and passenger vehicles seating 11+ including driver
• ✓Federal carriers: trucks registered 4,500 kg and greater, and passenger vehicles seating 11+ including driver
• ✓A trip inspection is required as part of the road test for Class 1, 2 and 3 licences

During the walk-around, inspect under the hood components common to all vehicles plus air brake components on equipped vehicles.

• ✓Check radiator, fan, belts, fluid levels, air filter and battery for defects and secure mounting
• ✓On air brake vehicles check air compressor mounting, brake chambers, slack adjuster angle and push rod travel
• ✓Check that air lines have no leaks, kinks, cuts, abrasions or cracks
• ✓Check steering, hoses, shock absorbers and suspension for wear or damage

For combination vehicles, inspect the fifth wheel, kingpin, coupling hardware and safety devices.

• ✓Fifth wheel coupler bolt must be secure, slider locked, plate flush to the apron with no daylight visible
• ✓Fifth wheel locking jaws must be closed and kingpin enclosed
• ✓Kingpin, pintle hitch eyehook, hitches, chains and cables must not be worn, cracked or broken and must be securely attached

A step-by-step air brake test is a guide for verifying the air brake system on tractor-trailers. Specific pressure thresholds must be memorized for the exam.

• ✓Tractor protection: trailer air supply valve should pop out at 40-60 PSI (276-414 kPa); low air warning by 60 PSI (414 kPa)
• ✓Park control valve should pop out at 20-45 PSI (138-311 kPa)
• ✓Governor cut-out at 120-135 PSI (828-931 kPa); cut-in is 20-25 PSI (138-172 kPa) less than cut-out
• ✓Air leak test: max 4 PSI (28 kPa) loss for power units plus 2 PSI (14 kPa) per trailer over 2 minutes with full brake applied

Provincially regulated carriers must complete trip inspection reports on trucks at 11,794 kg and greater and passenger vehicles seating 11 or more. Federally regulated carriers must do so on trucks at 4,500 kg and greater.

• ✓Provincial: trucks 11,794 kg and greater require trip inspection reports
• ✓Federal: trucks 4,500 kg and greater require trip inspection reports
• ✓Passenger vehicles seating 11 or more including driver require reports

A truck, tractor and towed trailer are inspected using Schedule 1; a converter dolly is inspected as part of the trailer it carries. Carriers must supply drivers with the schedule, which must be produced on demand by an officer.

• ✓Truck, tractor and towed trailer use Schedule 1
• ✓A converter dolly is inspected as part of the trailer it carries
• ✓Carriers must supply drivers with a copy of the inspection schedule
• ✓Driver must produce the schedule and report on demand of a peace officer

Before beginning an inspection, park on level terrain away from traffic, set the parking/spring brake, place a manual transmission in low gear, shut off the engine, and chock the wheels with blocks at least 15 by 15 centimetres.

• ✓Park on level terrain safely away from traffic
• ✓Set parking/spring brake and place manual transmission in low gear
• ✓Shut off the engine before inspecting
• ✓Chock the wheels; minimum square block size is 15 by 15 centimetres

Perform a walk-around (circle check) before starting any trip. It may be done in any order but must make a complete circle around the vehicle and cover every regulated item, with defects recorded and reported.

• ✓Do a walk-around check before starting any trip
• ✓Always make a complete circle around the vehicle
• ✓Every regulated inspection item must be inspected
• ✓Record and report any discovered defect

Inside the vehicle check seat and mirrors, seat belt, brake and clutch pedals, steering play, gauges, wipers, defroster, heater, horn and engine operation. Truck-tractors also verify air pressure build-up time and test service brakes.

• ✓Adjust seat, mirrors and seat belt properly
• ✓Steering must have no excessive play or slack
• ✓All gauges and warning lights must work
• ✓Test service brakes by driving forward slowly and stopping
• ✓Air pressure build-up time must be adequate for air brake units

Rest and check stops provide a break and allow checking the vehicle after time on the road. Ensure the vehicle is completely off the road, avoid stopping at the bottom of a hill, and check lights, air leaks, wheels, load and brakes.

• ✓Make sure the vehicle is completely off the road
• ✓Do not stop at the bottom of a hill or on an uphill slope
• ✓Choose stops that don't require backing to enter or exit
• ✓Check lights, air leaks, wheels, load security and brake adjustment
• ✓Schedule stops according to NSC requirements and company policy

All commercial vehicles or combinations over 4,500 kg must report to inspection stations when highway lights are flashing. Loaded vehicles drive across the scale; empty vehicles use the adjacent lane. Follow the light board instructions.

• ✓All commercial vehicles over 4,500 kg must report when station lights are flashing
• ✓Loaded vehicles drive slowly across the scale lane; empty vehicles use the adjacent lane
• ✓Follow STOP, BACK UP and PARK light board instructions
• ✓If PARK is activated, bring all vehicle and driver documents to the scale building

Drivers must complete and sign a report and cannot drive unless an inspection was conducted within the previous 24 hours. Other persons may conduct inspections. Schedule 1 is used for trucks, tractors and trailers.

• ✓A driver cannot drive a truck or tow a trailer unless an inspection was done within the previous 24 hours
• ✓A truck, tractor and towed trailer are inspected using Schedule 1; a converter dolly is inspected as part of the trailer
• ✓A person other than the driver who inspects and signs is legally responsible for that inspection
• ✓The driver must monitor vehicle condition for defects while en route

Buses and ambulances have unique inspection items beyond common items, including warning lights and safety equipment.

• ✓School bus: check alternating amber/red flashing lights, pedestrian safety crossing arm, stop arm, crossover mirror and retro-reflective tape
• ✓School bus rear: check white flashing strobe light and rear door emergency buzzer/seal
• ✓Ambulance: check emergency lights and patient compartment medical equipment, fire extinguisher and warning device
• ✓Bus interior: check fire extinguisher, first aid kit, emergency exits, wheelchair restraints and securely fastened passenger seats

Inside the vehicle, check seat, mirrors, controls, gauges, and operation of key systems before driving.

• ✓Check seat belt, brake and clutch pedal feel, steering play, gauges/warning lights and fuel level
• ✓Check windshield wipers/washer, defroster, heater, horn and backing alarm
• ✓Truck-tractor: check air pressure build-up time, air pressure drop when brakes applied, and test service brakes at slow speed
• ✓Listen for unusual engine and clutch noises

A post-trip inspection at the end of a shift lets you arrange repairs before the next trip and report problems found during the trip. School buses require additional checks for lost articles, sleeping children, floor cleaning and emergency equipment.

• ✓Do a post-trip inspection at the end of a shift
• ✓Report any problems discovered during the trip
• ✓School buses: inspect for lost articles and sleeping children
• ✓School buses: check emergency equipment, tires and fluid leaks