Inspección del vehículo — examen de práctica 2026

IncorrectoRespuesta correcta: A — To keep an unsafe vehicle off the road, for the driver's own sake and for everyone sharing it.

Every other benefit of an inspection, fewer breakdowns, less downtime, cleaner audits, is downstream of one purpose: keeping an unsafe heavy vehicle from being taken onto a public road where its failure hurts people.

The belief that pre-trip inspection is an administrative chore owed to the employer, rather than a safety barrier the driver personally owns.

IncorrectoRespuesta correcta: A — It keeps anyone else from starting the vehicle or moving it while you are alongside and underneath it.

You are about to put your hands and head next to the wheels of a vehicle heavy enough to kill you without noticing. The key in your pocket is the only guarantee that nobody else can put it in gear.

Treating the key step as a procedural formality in a checklist, rather than as lockout protection for the person about to work around the running gear.

IncorrectoRespuesta correcta: B — It removes the hazard while it is still only a repair, before it strands you or causes a crash.

A defect does not wait for a convenient moment. Found in the yard it is a repair order; found at highway speed it is a breakdown in a traffic lane or a crash, and the driver is inside the vehicle either way.

The idea that a known defect is acceptable to run on as long as it has been written up. Reporting a defect is not the same as removing the hazard.

IncorrectoRespuesta correcta: C — Three red reflective triangles, or six fuses, or three liquid-burning flares.

The requirement is for a complete set of one type of device, not a mixture. Carrying a partial set of two kinds leaves you unable to mark the vehicle properly when you are stopped in a traffic lane.

Mixing up the warning devices that mark a stopped vehicle with the other required emergency items. The fire extinguisher and spare fuses are separate requirements, not substitutes for triangles.

IncorrectoRespuesta correcta: B — How tight each belt is and how worn, against the give that belt should have when properly adjusted.

A belt drives the alternator, water pump or air compressor by friction. Slack it enough and it slips, so the battery stops charging or the compressor stops filling the air tanks, all while the belt still looks perfectly intact.

Grading belts pass or fail on whether they are unbroken, which misses the loose belt that quietly stops driving a critical accessory long before it ever snaps.

IncorrectoRespuesta correcta: A — A yellow lamp on the trailer's left rear that comes on and stays on.

The trailer reports its own ABS condition on its own lamp, and that lamp sits at the left rear. Like the dash lamp, it should light and then go out; one that remains lit means the trailer's antilock function is not available.

Expecting every fault on the combination to appear on the dashboard, so the trailer's own indicator is never looked at and its ABS fault is never noticed.

IncorrectoRespuesta correcta: A — Keep the vehicle out of service until the defect is repaired or certified as not needing repair.

An uncertified safety defect means nobody has confirmed the vehicle is fit to drive. Once you know that, the decision to move it is yours, and so is the outcome when the hose wears through on a downgrade.

Believing that re-reporting a known defect discharges the driver's duty, when writing it down a second time changes nothing about the condition of the hose.

IncorrectoRespuesta correcta: C — It can carry exhaust gas into the space where the driver breathes and sleeps.

A leak routes combustion gas into the cab or bunk. Carbon monoxide degrades judgment before the driver notices anything is wrong, which is what makes it dangerous rather than merely annoying.

Grading an exhaust leak as a performance or noise problem, when the real hazard is a poisoned driver who cannot assess his own impairment.

IncorrectoRespuesta correcta: B — When one-fourth or more of the leaves are missing.

One-fourth is the line at which an inspector will stop the vehicle. It is not the line at which the spring became dangerous, and a lower count is no licence to keep driving.

Reading the out-of-service threshold as the point where the defect becomes dangerous. It is only the point where someone else will stop you; a single broken leaf can still shift and strike a tire.

IncorrectoRespuesta correcta: C — The antilock braking system is not working properly.

The lamp is designed to illuminate briefly at start-up to prove the bulb works, then extinguish. A lamp that stays lit is not confirming readiness; it is reporting a fault the system has already detected.

Reading a steady warning lamp as an 'on and ready' indicator, so a genuine ABS fault is interpreted as normal operation for months.

IncorrectoRespuesta correcta: A — Put right anything that affects safety, and state on the report itself that it was fixed or that no fix was needed.

The certification is what closes the loop. It is the carrier stating in writing that the reported condition was either corrected or examined and found not to require correction, so the next driver can rely on it.

Assuming a written-up defect can simply be queued for later maintenance, when a safety-related item must be resolved and the resolution certified, not deferred.

IncorrectoRespuesta correcta: A — It points to a brake fault, and the vehicle must be fixed before it is driven.

Pulling means the wheel ends are not braking evenly, so some are doing the work of others. At five miles per hour that is a tug; in an emergency stop it drags the vehicle out of its lane or folds a combination. Operating an unsafe vehicle is forbidden by federal and state law.

Judging brakes by whether the vehicle stops rather than by how it stops, which lets a serious imbalance pass because the mild test did not produce a dramatic result.

IncorrectoRespuesta correcta: C — Pump the pedal three times, then push it down hard and hold it for five seconds; it must not sink.

Pumping removes the reserve assist so the pedal reflects the hydraulic circuit alone, and holding pressure is what exposes a slow leak. A pedal that sinks under steady pressure is losing fluid somewhere.

Accepting a pedal that feels firm on a single press as proof of a sealed system, when only sustained pressure reveals the slow leak that finishes failing on a long downgrade.

IncorrectoRespuesta correcta: C — A single day, long enough to pass what you found to whoever drives it next.

The in-cab copy exists for one job: handing your findings to whoever climbs into this seat next. A day is long enough for that handoff, and the carrier keeps its own copy for the record.

Confusing the copy carried in the cab, which is a handoff between drivers, with the carrier's file copy kept for record-keeping.

IncorrectoRespuesta correcta: C — The vehicle is placed out of service and may not be driven until the defect is corrected.

An out-of-service order is not a penalty to be paid and driven away from. It is a prohibition on moving the vehicle, and it stays in force until the condition that earned it has been corrected.

Treating an out-of-service order like a citation or a deadline to comply with later, rather than an immediate ban on operating that vehicle.

IncorrectoRespuesta correcta: B — Repetition fixes the whole route in memory, so a step left out is one you notice.

A repeated routine turns coverage into a habit. When the sequence is always the same, an omission feels wrong, which is the only reliable defence against a distracted morning.

Reading a standard inspection routine as a legally mandated sequence rather than a memory discipline. What is required is that nothing gets missed, and repetition is what delivers that.

IncorrectoRespuesta correcta: A — With your safety belt fastened and the brake set, select a low gear and pull gently forward against it.

Only applying load proves holding force. Gently pulling against the set brake asks the question that matters, whether it will hold this vehicle at this weight, which no indicator lamp and no level surface can answer.

Confirming that the brake is applied instead of confirming that it holds. Contaminated shoes or slack adjustment will show 'set' on the dash and still let a loaded vehicle walk away on a grade.

IncorrectoRespuesta correcta: C — How the vehicle sits and what is under it: damage, a lean to one side, fresh fluid on the ground, and anything in the way of moving it.

The approach is the only moment you can see the whole vehicle at once. A lean, a puddle, or a low branch over the exit path are all readable from ten paces and invisible once you are up against the bumper.

Starting the inspection at the first component you touch, which throws away the overall stance of the vehicle and whatever dripped out of it overnight.

IncorrectoRespuesta correcta: C — Use your senses, looking, listening, smelling and feeling for anything abnormal.

Most developing failures announce themselves to a person long before they reach a sensor. A hot-brake smell, a new vibration, or the slap of a separating tread are all detectable from the driver's seat if you are paying attention.

Trusting warning lamps as a complete monitoring system, when the vehicle has no sensor for most of the things that will strand or kill you.

IncorrectoRespuesta correcta: B — Only where a defect was written up and someone has certified it repaired or found not to need repair.

The signature is an acknowledgement of two specific things: that a defect was reported and that the carrier certified how it was resolved. On a report with nothing noted there is nothing for the driver to acknowledge.

Signing every report by reflex, which turns the signature into a meaningless habit instead of a deliberate check that a known defect was actually dealt with.

IncorrectoRespuesta correcta: B — Come up to the normal range within seconds of starting.

Oil pressure is not a warm-up reading. The pump is turning the moment the engine turns, so a delay means the bearings are running without a film of oil right now, and that damage cannot be undone.

Grouping oil pressure with the temperature gauges that legitimately climb slowly, so a dangerously slow pressure rise is excused as normal warm-up behaviour.

IncorrectoRespuesta correcta: B — Clearance lamps and reflectors at the rear have to show red; amber back there tells a following driver he is looking at the front of a vehicle.

Lamp colour is information, not decoration: amber toward the front, red at the rear. An amber clearance lamp at the back of a trailer at night tells an approaching driver the vehicle is facing him, which is exactly the wrong conclusion.

Believing that a lamp which lights is a lamp which passes, so colour errors are dismissed as cosmetic when they actively misinform other drivers.

IncorrectoRespuesta correcta: C — It should climb from 50 psi to 90 psi in no more than three minutes.

The build-up rate, not just the final pressure, tells you whether the compressor can keep up. A system that fills slowly will still reach cut-out in the yard but cannot replace the air that repeated brake applications take out on a long grade.

Judging the air system solely by whether it eventually reaches cut-out pressure, which hides a weak compressor until the moment you need air faster than it can make it.

IncorrectoRespuesta correcta: A — That the parking brakes are applied, the wheels chocked, or both.

You are about to stand in front of a loaded vehicle with your hands inside it. Securing it against rolling protects the inspector, which is why this comes before anything is opened.

Thinking of the parking brake and chocks as yard equipment for parked trailers, rather than personal protection for whoever is standing ahead of the front wheels.

IncorrectoRespuesta correcta: B — 4/32 inch on the front tires and 2/32 inch on the other tires.

Front tires get the deeper minimum because they carry the vehicle's directional control; a steer tire that loses grip or blows takes the driver's ability to steer with it.

Applying the familiar 2/32 inch passenger-car figure to every position, which leaves the two tires that steer a loaded combination with the least reserve of any on the vehicle.