Module 3: The Supply Circuit +7Alberta · CDL · English

Supply tanks have lanyard pulls; service tanks have lanyards or manual drain valves. Regular draining prevents contamination accumulation. Tanks do not drain properly until air pressure is depleted and contamination settles and drips from the tank.

• ✓Pull the supply tank lanyard often during the day, pre-trips, en-route inspections, and fuelling
• ✓Drain tanks completely at the end of the shift if moisture is accumulating
• ✓Tanks do not drain properly until air pressure is depleted and contamination settles

The air compressor generates air pressure for the brake system. On engine blocks not originally designed for air systems, the OEM adds a belt-driven compressor with mounting brackets. During the daily trip inspection, drivers must check the compressor for loose fasteners, cracked hubs, loose spindle nuts, and proper belt tension.

• ✓Shake the top of the compressor to check for loose fasteners and brackets
• ✓Move pulleys side to side to check for cracked hubs or loose spindle nuts
• ✓Pull the belt to check for appropriate tension at the middle of the longest run

The first tank receiving air pressure is called the supply, wet, or purge tank interchangeably. 'Supply' is the formal term; 'wet tank' is common because it captures the bulk of contamination. Most air dryers manage their own purge air rather than relying on the supply tank, except the AD-IS system.

• ✓Supply is the formal term for the first tank receiving air pressure
• ✓The wet tank captures the bulk of contamination
• ✓Other than the AD-IS system, most dryers manage their own purge air

The supply tank lanyard should be pulled often during the day, during pre-trips, en-route inspections, and fuelling. This ensures contamination is not accumulating. If moisture accumulates, drain tanks completely at the end of the shift. Tanks do not drain properly until air pressure is depleted and contamination settles.

• ✓Pull the supply tank lanyard often throughout the day and during inspections
• ✓Drain tanks completely at the end of the shift if moisture is accumulating
• ✓Tanks do not drain properly until after air pressure is depleted and contamination settles

Safety valves protect the system from over-pressurization. They may be external, or thread in so the top is flush with the bung. Most air brake vehicles have safety valves in both the air dryer and supply tank; some have one only in the air dryer.

• ✓Most air brake vehicles have safety valves in both the air dryer and supply tank
• ✓Some air brake vehicles have a safety valve only in the air dryer

Older air dryers were after-cooler types recognized by cooling fins, collecting contamination in a sump. Modern dryers use desiccant that adsorbs moisture, which is blown off during purging (back-flushing). Most dryers manage their own purge air; some use a separate tank or supply tank air.

• ✓Older after-cooler air dryers are recognized by cooling fins on the sides
• ✓Modern dryers use desiccant that adsorbs moisture and is purged by back-flushing

The AD-IS (Air Dryer Integrated Solution) integrates the air dryer, purge reservoir, and charging valve components into one module. It collects and removes contaminants in solid, liquid, and vapour form before they enter the brake system, eliminating the need for daily manual tank draining.

• ✓AD-IS eliminates the necessity for daily manual draining of air tanks
• ✓Drain lanyards should still be pulled regularly to confirm the dryer is working properly

Air brake antifreeze is methyl-alcohol with a lubricant to prevent rubber components from drying out. Pure alcohol damages the air dryer desiccant, so it must not be added ahead of the dryer. Some trailers have desiccant dryers that alcohol would damage, indicated by a warning decal.

• ✓Pure alcohol damages air dryer desiccant, so avoid adding alcohol ahead of that component
• ✓Alcohol added into the compressor pressure line goes directly into and damages the dryer

The supply tank can be identified by looking for the safety valve. The OEM often labels the tank. Air enters from the air dryer, and red/green lines go to respective service tanks. A 1/4 inch (6 mm) line runs to the governor, and the drain lanyard is visible underneath.

• ✓Identify the supply tank by looking for the safety valve
• ✓The air dryer feeds air into the supply tank, which then feeds the service tanks

Safety valves protect the system from over-pressurization. They may be mounted externally or thread in flush with the bung. Most air brake vehicles have safety valves in both the air dryer and supply tank; some only in the air dryer.

• ✓Most air brake equipped vehicles have safety valves in both the air dryer and supply tank
• ✓Some vehicles have a safety valve only in the air dryer
• ✓Safety valves can be mounted externally or threaded in flush with the tank bung

The supply tank can be identified by locating the safety valve. Air comes in from the air dryer (black line), red and green lines go to service tanks, and a 1/4 inch (6mm) line goes to the governor. The drain lanyard is visible underneath.

• ✓Identify the supply tank by looking for the safety valve
• ✓The 1/4 inch (6mm) line from the supply tank goes to the governor
• ✓The air dryer heating element keeps the purge valve from freezing open

There is no fixed direction for turning the wrench when adjusting a manual slack adjuster; it may turn right or left depending on how the slack adjuster is installed. What matters is that the s-cam shaft rotates in the direction of brake application, pressing the linings toward the drum. There is no fixed relationship between the s-cam shaft rotation and the direction of wrench rotation.

• ✓Turn the adjuster cap screw so the s-cam shaft rolls in the direction of brake application, pressing linings toward the drum
• ✓There is no relationship between s-cam shaft rotation and wrench rotation direction
• ✓The wrench may need to be turned right or left depending on how the slack adjuster is installed

When adjusting a manual slack adjuster, the push rod's behaviour confirms whether adjustment is correct. If the push rod starts pulling out of the brake chamber, the wrench is being turned incorrectly. If the push rod moves into the brake chamber, the brake was previously adjusted incorrectly.

• ✓If the push rod pulls out of the brake chamber, the wrench is being turned the wrong way
• ✓If the push rod moves into the brake chamber, the brake was previously mis-adjusted

After tightening a manual slack adjuster, back off approximately one-third of a turn as a general guide. The exact amount varies depending on the person and how securely the brake was previously tightened.

• ✓Back off approximately one-third of a turn after tightening
• ✓The amount to back off varies with how tightly the brake was previously secured

During the test, the instructor marks each task the student did NOT correctly perform using the corresponding check box. At the end of the test, the percentages beside each incorrectly performed task are added together (e.g. 5% + 5% + 10% = 20%). A total score equal to or more than 25% results in a fail.

• ✓Only tasks performed INCORRECTLY are marked with a check
• ✓A total score of 25% or more results in a failed test
• ✓Percentages of all incorrect tasks are summed to determine the total score

If the student fails the test, the same form must be used for the retest. Steps 2 through 8 (dating, checking boxes, scoring, and signatures) must be repeated. Importantly, a retest cannot be done on the same day as the original test.

• ✓The same form must be used for any retest
• ✓A retest cannot be done on the same day as the original test
• ✓Steps 2 to 8 must be repeated on another day for the retest

Before starting the air brake practical test, the student's first and last name and operator's licence number must be completed. The date of the test must be written in year/month/day format. The instructor's first and last name and their licence/certificate number must be recorded, which may be done before or after the test.

• ✓Student first and last name plus operator's licence number must be completed prior to starting the test
• ✓Date must be written in yyyy-mm-dd format before the test begins
• ✓Instructor name and licence/certificate number can be recorded before or after the test

At the end of the test, the instructor must sign their name to verify the test's results. The student must also sign to verify the test results. Both signatures are required to complete the form.

• ✓Instructor must sign at the end of the test to verify results
• ✓Student must sign to verify the test results
• ✓Signatures are completed at the end of the test

The air brake practical test has a time limit of 15 minutes. If completing the document electronically, use the Save and Print buttons to save and print the form for record keeping.

• ✓The practical test has a 15 minute time limit
• ✓Electronic forms should be saved and printed for record keeping

Every vehicle used to carry Class 1 material (Explosives) must carry a document signed by the owner or the person leasing the vehicle. This document identifies the driver(s) authorized to operate or accompany the vehicle.

• ✓A signed document from the owner or lessee is required for Class 1 explosives vehicles
• ✓The document must name the driver(s) authorized to operate or accompany the vehicle

If dangerous goods placards and panels are lost, damaged, or defaced during the trip, the carrier is responsible for replacing them.

• ✓The carrier must replace placards and panels that are lost, damaged, or defaced during a trip
• ✓Placards and panels must be maintained in proper condition throughout transport

Every vehicle used to carry Class 1 material (Explosives) must carry a signed document indicating who is authorized to operate or accompany the vehicle.

• ✓The document must be signed by the owner or the person leasing the vehicle
• ✓It must indicate the name of the driver(s) authorized to operate or accompany the vehicle
• ✓This applies to every vehicle carrying Class 1 Explosives

For complete information on transporting dangerous goods, drivers can contact the Dangerous Goods, Vehicle and Rail Safety Branch in Edmonton.

• ✓Edmonton contact: 780-422-9600
• ✓Toll free from anywhere in Alberta: 1-800-272-9600 with 24-hour service

No one may handle, offer for transport or transport dangerous goods unless trained or working in direct contact with someone trained. Carriers must ensure proper training and issue a signed Dangerous Goods Training Certificate.

• ✓No one may handle, offer for transport or transport dangerous goods unless trained or working in direct contact with a trained person
• ✓The employer must be satisfied with the training and sign the certificate of training
• ✓A driver must produce the certificate of training if asked by a dangerous goods inspector

There are nine hazard classes of dangerous goods, some with divisions: explosives, gases, flammable liquids, flammable solids, oxidizers/organic peroxides, toxic/infectious substances, radioactive materials, corrosives, and miscellaneous.

• ✓Class 1 is explosives, Class 2 is gases, Class 3 is flammable liquids with a closed-cup flash point below 60.5°C
• ✓Class 4 is flammable solids/spontaneous combustion/water-reactive, Class 5 is oxidizers and organic peroxides, Class 6 is toxic and infectious substances
• ✓Class 7 is radioactive materials, Class 8 is corrosive materials, Class 9 is miscellaneous products or substances
• ✓Class 2 divisions are 2.1 flammable, 2.2 non-flammable non-toxic, and 2.3 toxic compressed gas

When a dangerous incident such as a leak, collision or release occurs, the person in charge of the goods must immediately notify several parties.

• ✓Immediately notify the local police, the vehicle owner, the employer, and the owner of the dangerous goods consignment
• ✓Notify the Alberta Government Co-ordination and Information Centre (CIC) at 1-800-272-9600

Drivers must carry the shipping document, waste manifest or other required document, positioned within reach in the cab. Special rules apply to parked trailers and multiple deliveries.

• ✓When in the cab, documents must be within reach or in a pocket on the driver's door; when not in the cab, on the seat or in the door pocket
• ✓For a parked detached trailer, the person in charge of the parking area keeps a copy, or a copy in a waterproof container is attached to the trailer
• ✓For multiple deliveries by tank truck, tank trailer or gas cylinders, the change in quantity must be shown on the shipping document after each delivery

Safety marks are supplied by the consignor, but the driver must ensure the vehicle has all proper safety marks before loading. Marks must stay on until no hazard exists.

• ✓Safety marks, placards or orange panels must be on each side and each end of a trailer or transport unit before loading
• ✓Placards may be moved to the front of the lead vehicle so safety marks are visible
• ✓Safety marks must remain until no hazard exists, meaning goods are unloaded and the container cleaned and purged of all residues

The air brake knowledge test is conducted by a Registry Agent, comprises thirty multiple choice questions randomly chosen from a question bank. The pass mark is 83%, allowing a maximum of five incorrect answers.

• ✓Knowledge test has 30 multiple choice questions with a pass mark of 83%
• ✓A maximum of five incorrect answers is permitted to pass

The Practical Test form records student performance on the air brake pre-trip inspection and brake adjustment on a tractor-trailer. Each task is weighted 5%, 10% or 15%. Errors totalling 25% or more result in a test failure, as 80% is required to pass.

• ✓Each task on the practical test has a weight of 5%, 10% or 15%
• ✓Errors totalling 25% or more result in a test failure
• ✓80% is required to pass the practical test
• ✓Students who fail must retake the test on another day

The knowledge test is comprised of thirty multiple choice questions randomly chosen from a question bank. The pass mark is 83%, allowing a maximum of five incorrect answers. It is conducted by a Registry Agent for a cost, and students are encouraged to write shortly after completing the course.

• ✓The knowledge test has 30 multiple choice questions with a pass mark of 83%
• ✓A maximum of five incorrect answers is allowed to pass the knowledge test

Practical tests are conducted after completing practical training sessions. Each student's practical test is fifteen minutes in length with no other students present, conducted one instructor to one student. Retests are allowed on another day.

• ✓Practical test is 15 minutes with no other students present
• ✓Testing must be one instructor to one student; retest allowed on another day

The air brake course has three portions: a classroom session, practical training sessions, and practical tests. The classroom session is a prerequisite to practical training. A completed classroom session, practical training session, and practical test lead to program completion, followed by a knowledge test at a Registry Agent.

• ✓The classroom session is a prerequisite to offering practical training sessions
• ✓A student's practical test is fifteen minutes in length with no other students present
• ✓Students who fail are allowed a retest on another day

A maximum of 18 students are permitted per classroom session. A maximum of three students are permitted per air brake equipped vehicle and instructor in each practical training session. Students may retest on another day if unsuccessful.

• ✓Maximum of 18 students per classroom session
• ✓Maximum of three students per practical training session per vehicle and instructor

A medical report is required to upgrade to Class 1, 2 or 4. Medical forms must be completed by a doctor or nurse practitioner. Reports are needed at first application and at set intervals based on age. Drivers are legally responsible to report any disease or disability affecting safe driving.

• ✓Medical report required to upgrade to Class 1, 2 or 4
• ✓Medical report renewed every 5 years until age 45
• ✓Every 2 years from age 45 to 65
• ✓Every year after age 65
• ✓Driver must report any disease or disability interfering with safe operation

To learn to drive a commercial class vehicle you must hold at least a Class 5 or Class 5 GDL licence. You may not apply for commercial classes while in the GDL program. You do not need an air brake endorsement while learning to operate an air brake equipped vehicle.

• ✓Must hold at least a Class 5 or Class 5 GDL licence to learn commercial classes
• ✓Cannot apply for commercial classes while in the Graduated Driver Licensing program
• ✓No air brake endorsement needed when learning on an air brake equipped vehicle
• ✓A 10-day waiting period applies to non-GDL Class 5/5-6/6 applicants from other Canadian jurisdictions re-classing to Classes 1-4

Driving with the wrong licence class is against the law. It is also an offence for a vehicle owner to allow their vehicle to be driven by someone without the proper class of licence.

• ✓Driving with the wrong licence class is illegal
• ✓A vehicle owner commits an offence by allowing an improperly licensed driver to operate their vehicle
• ✓A fee is charged for each knowledge test, road test and re-classification

To operate any vehicle with air brakes you must complete the Alberta Air Brake Program at a licensed driving school or entity and obtain the air brake 'Q' endorsement on your licence.

• ✓The 'Q' endorsement is required to operate any vehicle with air brakes
• ✓You must complete the Alberta Air Brake Program to obtain the endorsement
• ✓Detailed air brake information is found in the Alberta Air Brake Manual

Detailed air brake information is in the Alberta Air Brake Manual, given when completing the Alberta Air Brake Program at a licensed driving school or entity. Completing the program is required for the Q endorsement.

• ✓You must complete the Alberta Air Brake Program to obtain the air brake Q endorsement
• ✓The Q endorsement is required to operate any vehicle with air brakes

Do not use a cellular phone or other electronic devices while driving. This includes making/receiving calls and sending/receiving texts, and applies even to hands-free phones. If you must communicate, stop in a safe and legal place first.

• ✓Do not use a cellular phone to make/receive calls or send/receive texts while driving
• ✓The prohibition applies to hands-free cellular telephones as well
• ✓Stop in a safe and legal place to make or receive calls or texts
• ✓The Traffic Safety Act includes fines for hand-held cell phone use, texting, emailing, using laptops, video games, cameras, and programming portable audio players

The Traffic Safety Act includes fines for specific distractions: using hand-held cell phones; texting/emailing; using electronic devices (laptops, video games, cameras, video entertainment displays); programming portable audio players; entering GPS information; reading printed materials; writing, printing or sketching; and personal grooming.

• ✓Fineable activities include entering information on GPS units, reading printed materials, writing, printing or sketching
• ✓Personal grooming while driving is a fineable distraction

Do not use a cellular phone or other electronic devices while driving. This includes making/receiving calls and sending/receiving texts, and applies even to hands-free phones because the distraction takes attention from driving. If you must use a phone, stop in a safe and legal place.

• ✓Do not make/receive calls or send/receive texts while driving, including with hands-free devices
• ✓Stop in a safe and legal place if you need to use a phone
• ✓Fineable distractions include hand-held cell phones, texting/emailing, using laptops, video games, cameras, video displays, programming audio players, entering GPS info, reading printed materials, writing, sketching, and personal grooming

The distracted driving law applies to all vehicles as defined in the Traffic Safety Act, including cars, motorcycles, motor homes, truck tractors, farm vehicles and bicycles.

• ✓The law applies to all vehicles defined in the Traffic Safety Act
• ✓Covered vehicles include cars, motorcycles, motor homes, truck tractors, farm vehicles and bicycles

Under the Traffic Safety Act, emergency vehicles include police service vehicles, fire response units, ambulances and gas disconnection units responding to a call. Their drivers may use hand-held communication or electronic devices only when acting within the scope of their employment.

• ✓Emergency vehicles include police, fire response units, ambulances and gas disconnection units responding to a call
• ✓Emergency vehicle drivers may use hand-held devices only when acting within the scope of their employment

Certain activities are not restricted: using two-way/CB radios when escorting oversized vehicles, contacting one's employer, or during search/rescue and emergency management. Permitted display screens include affixed and pre-programmed (or voice-activated) GPS, vehicle system gauges, passenger transport dispatch systems, and logistical transportation tracking systems.

• ✓Two-way/CB radios are permitted for escorting oversized vehicles, contacting an employer, or search/rescue and emergency situations
• ✓GPS navigation is permitted only if affixed to the vehicle and programmed before driving, or voice-activated — you cannot hold the unit or manually enter information while driving
• ✓Permitted screens include vehicle system gauges, passenger dispatch systems, and logistical transportation tracking systems

Drivers using dispatch systems for passenger transport or logistical tracking devices for commercial purposes can have mobile data computers installed and activated, but should not type information into these devices while driving.

• ✓Mobile data computers may be installed and activated in vehicles for commercial dispatch/tracking use
• ✓Drivers should not type information into these devices while driving

CB radios and 'Mike phones' are exempt for commercial purposes and search/rescue services. Hand-held use is allowed to communicate with the driver's employer or during emergency management situations, including reporting extreme weather or roadway hazards like collisions.

• ✓Hand-held CB radios or Mike phones are allowed to communicate with an employer or during emergency management
• ✓Communicating extreme weather or roadway hazards (such as a collision) can fall under the emergency scenario category
• ✓Enforcement officers evaluate specific situations to determine compliance

Some activities are not restricted under the distracted driving law, including using two-way or hand-held radios (such as CB radios) when escorting oversized vehicles, contacting an employer, or participating in search, rescue and emergency management.

• ✓Two-way and hand-held CB radios are allowed when escorting oversized vehicles or contacting an employer
• ✓Radio use is allowed during search, rescue and emergency management situations

Certain display screens are permitted while driving: a GPS navigation system affixed to the vehicle and programmed before driving (or voice activated); a gauge/instrument/device providing vehicle system or location info; a passenger transport dispatch system; and a logistical transportation tracking system.

• ✓A GPS must be affixed and pre-programmed or voice activated; you cannot hold it or enter info while driving
• ✓Permitted screens include vehicle-info gauges, passenger dispatch systems, and commercial logistical tracking systems

Drivers who use dispatch systems for transporting passengers or logistical tracking devices for commercial purposes may still have mobile data computers installed and activated. However, drivers should keep focus on the road and must not type information into these devices while driving.

• ✓Mobile data computers may be installed and activated in commercial vehicles
• ✓Drivers must not type information into these devices while driving

Tour bus drivers must comply with the distracted driving law and must not drive distracted. Hands-free units and innovative technology solutions are available to provide passenger information while remaining compliant.

• ✓Tour bus drivers must be in compliance with the law and must not drive distracted
• ✓Hands-free units and technology solutions must be used to provide passenger information

Under the Traffic Safety Act, emergency vehicles include police service vehicles, fire response units, ambulances and gas disconnection units responding to a call. Drivers of these vehicles may use hand-held communication or electronic devices only when acting within the scope of their employment.

• ✓Emergency vehicles include police, fire, ambulance and gas disconnection units responding to a call
• ✓Emergency vehicle drivers may use hand-held devices only within the scope of their employment