Free Alberta Air Brake (Q) Exam Flashcards

The credential added to an Alberta driver's licence that authorizes operating a vehicle with an air brake system. Class 1, 2, 3, 4, and 5 licence holders need it before driving any air-brake-equipped vehicle, and Class 1 applicants must earn it before their Class 1 licence.

30 multiple-choice questions taken electronically at an Alberta registry agent, in English only and with no time limit; paper and translated versions are not offered.

25 of the 30 knowledge-test questions must be answered correctly (83.33%). The test also ends automatically the moment a candidate answers 6 questions incorrectly, even before reaching question 30.

A candidate who does not pass must wait until a different day to retest. Alberta sets no limit on the total number of attempts, but the knowledge-test fee is charged again for every attempt.

Classroom training of at least 6.5 hours, then practical training, then a one-on-one practical assessment with a 15-minute limit, all through a licensed driver training school. Passing earns the Notice of Air Brake Program Completion form a registry agent needs before the knowledge test.

A single-motor farm vehicle with air brakes does not need a Q endorsement. A farm vehicle combination that requires a Class 1 licence still needs the Q endorsement and proof of air brake training.

Alberta's Commercial Driver's Guide defines air brakes as brakes initiated by air pressure from an engine-driven compressor, sent through hoses, reservoirs, and control valves to all of the vehicle's foundation brakes.

Some axles use air-actuated foundation brakes while other axles on the same vehicle use hydraulic foundation brakes; this combination still requires a Q endorsement or a Class 1 licence.

The air compressor only boosts a hydraulic system that operates all of the vehicle's foundation brakes, similar to a power-assist function. Because every foundation brake is hydraulic, a Q endorsement is NOT required.

During Alberta's trip air brake inspection, building air pressure to system maximum should confirm the governor cuts out the compressor between 120 and 135 PSI.

Pumping the service brakes to reduce air pressure should show the governor cutting the compressor back in 20 to 25 PSI below the cut-out pressure just confirmed.

With the engine at a fast idle of about 1200 RPM, air pressure must rise from 50 to 90 PSI within three minutes; a slower build-up points to a weak compressor, a slipping belt, or a leak.

The first reservoir compressed air reaches after leaving the compressor. Hot compressed air cools here, so moisture and oil condense out before the air continues to the rest of the system.

Pull the supply tank drain often - during trip inspections, en-route checks, and fuelling - to confirm contamination is not building up. If moisture is accumulating, drain the tanks completely at the end of the shift; a tank only drains properly once its air pressure is gone.

Cools compressor discharge air and passes it through a drying element to remove moisture before that air reaches the reservoirs, cutting the corrosion and freeze risk moisture would otherwise create.

In Alberta's trip air brake inspection, the low air pressure warning should come on by 60 PSI (414 kPa) as pressure drops, and the warning light should go out by 60 PSI as the compressor rebuilds pressure.

Stop as soon as it is safe to do so and rebuild air pressure before continuing; do not keep driving on a system that has already signalled unsafe reservoir pressure.

A dual air brake system shows separate reservoir gauges for the primary and secondary circuits, letting the driver monitor each circuit's available pressure independently.

A service brake application can never exert more force than the air pressure actually stored in the reservoir at that moment, so low reservoir pressure directly reduces available braking force.

Spring parking brakes are held in the released position by air pressure and apply automatically, driven by strong internal springs, whenever that air is exhausted or lost.

During Alberta's trip inspection, pumping the foot valve after pushing in the yellow park control valve should cause it to pop back out between 20 and 45 PSI.

Applying the service brakes hard while the spring parking brakes are already applied stacks spring force and air force on the same foundation-brake parts, which can bend or break components; avoid holding both applied at the same time.

A technician manually compresses (cages) the very strong parking-brake spring, most often to move a vehicle that has no air pressure. Because caging removes that wheel's parking-brake hold, the wheels must be chocked first.

Splitting service braking into independent primary and secondary circuits means a leak or failure in one circuit still leaves usable, though reduced, braking through the other circuit.

These valves let air flow from the supply reservoir into the primary and secondary service reservoirs but block it from flowing back, so a supply-side failure cannot drain the service air a driver still needs to stop.

One reservoir gauge keeps dropping, the low air warning activates, and stopping power is reduced. Use a steady brake application rather than pumping, stop in a safe place, and have the vehicle repaired before continuing.

A plugged or collapsed line or a ruptured supply tank shows up as gauges that stop replenishing once pressure falls below governor cut-in. One-way check valves protect the service tanks, so all brakes still work, but only on the air already stored.

The one tractor air system failure in which a service circuit's brakes do not work during a service application: the steering axle brakes will not apply. Primary circuit air keeps the spring park brakes released while the driver makes a controlled stop.

Air pressure moves the brake chamber diaphragm and pushrod; the pushrod drives the slack adjuster, and the slack adjuster rotates the S-cam, which forces the brake shoes outward against the drum.

Out-of-adjustment brakes can feel normal in everyday driving and then fail when a hard stop or a long grade demands more of them. Pushrod stroke has to be physically checked, not judged from the driver's seat.

Automatic slack adjusters continually correct for normal lining wear during use, while manual slack adjusters must be adjusted by hand on a schedule; either type still needs its stroke checked during inspections.

Cranking an automatic slack adjuster by hand can hide a real problem, such as a worn foundation brake or a failing internal clutch, instead of fixing it; a technician should inspect and repair an out-of-spec automatic adjuster.

Alberta's guide warns that if the brakes are not adjusted properly, some brakes have to work harder than the others, which could cause a skid.

Measured with the service brakes fully applied, because a partial application will not show the full stroke. The CVSA out-of-service limits are 1 3/4 in (45 mm) for a standard Type 20 chamber, 2 in (51 mm) for a Type 30, and 2 1/2 in (64 mm) for a Type 30 long-stroke chamber.

A loss of braking power as the brakes overheat: the hot drum expands away from the shoes while friction between lining and drum falls. Brakes already out of adjustment run out of pushrod stroke sooner, so they fade first.

Alberta's guide advises downshifting before going over the top of a hill and using engine compression to control speed. Do not pump the brakes: pumping wastes air pressure, and on a long downhill grade it may leave too little pressure for the brakes to work properly.

Press the brake pedal with even, steady pressure, then ease off as the vehicle slows; just before it stops, release briefly to avoid a jerk, then reapply pressure to hold the vehicle in place.

The sum of the distance travelled during perception time, reaction time, air brake lag time, and the actual braking distance once the brakes are applying full force.

The time an average driver takes to recognize the need to stop, about three-quarters of a second; fatigue or distraction can make it longer.

The time between deciding to stop and actually pressing the brake pedal, also about three-quarters of a second under normal conditions; alcohol, drugs, and fatigue slow it further.

The roughly 4/10 of a second it takes compressed air to travel through the system and apply the brakes once the pedal is pressed; unlike hydraulic brakes, air brakes do not respond instantly.

Engine, exhaust, and driveline retarders help control speed, especially on grades, but they are not intended for emergency braking and cannot meet sudden or large braking demands; the service brakes must still do that work.

Carries reservoir air from the tractor to fill and maintain the trailer's own air reservoirs, and supports the trailer's automatic spring-brake application if that air supply is lost.

Carries the variable air-pressure signal that tells the trailer's service brakes how hard to apply, matching the pressure the driver sends from the tractor's foot valve.

During Alberta's tractor protection check, with both trailer air lines disconnected, the red trailer air supply valve should pop out at 40 to 60 PSI or higher.

Automatically shuts off air flowing toward the trailer if a supply line ruptures or the trailer breaks away, preserving enough air pressure for the tractor to stop on its own.

The trailer service brakes stop responding, so stopping distance increases dramatically. If the vehicle must be stopped quickly, pull the red trailer air supply valve to apply the trailer's spring (emergency) brakes.

With the park control valves pushed in, pressure rebuilt, and the engine off, hold a full service brake application for 2 minutes. After the system stabilizes, the maximum loss is 4 PSI (28 kPa) for a power unit plus an additional 2 PSI (14 kPa) per trailer.

The final trip-inspection step: after removing the wheel chocks and releasing the spring park brakes, the driver checks that the vehicle responds correctly to both the foot valve and, on a combination unit, the trailer hand valve.

Alberta's inspection list for vehicles with air brakes: compressor securely mounted; lines, fittings, hoses, and couplers in good condition; brake chambers secure; slack adjuster angle and pushrod travel acceptable; and air lines free of leaks, kinks, cuts, abrasions, or cracks.