Kansas CDL Combination flashcards

31 cards. Read the term and the definition here. The deck at the top of this page is optional.

Fifth-wheel jaw check

After coupling, verify the locking jaws are closed around the kingpin by looking underneath and by tugging the tractor gently against the set trailer brakes.

Tug test

With trailer brakes set, pull forward gently in low gear; if the tractor moves without resistance the trailer is not coupled, so stop and recouple.

Trailer hand valve

The dash valve that applies only the trailer brakes; used to test trailer brake operation, never as a parking brake because it can cause a jackknife.

Tractor protection valve

A valve that closes the tractor air supply to the trailer if the trailer breaks away or a line fails, causing the trailer emergency brakes to set automatically.

Emergency spring brakes

Trailer brakes held off by air pressure; when pressure drops below roughly 45 psi, springs apply the brakes automatically to stop the trailer.

Low-air warning

A buzzer and light must activate before air pressure drops below 60 psi; if the warning does not work, the vehicle is out of service.

Static air leak rate

With engine off and brakes released, leakage must not exceed 3 psi per minute; with the brakes applied, no more than 4 psi per minute.

Following distance rule

Allow one second per 10 feet of vehicle length below 40 mph, plus one extra second; above 40 mph add another second.

Off-tracking

The tendency of a trailer's rear wheels to follow a shorter path than the tractor's front wheels, greatest with long wheelbases and sharp turns.

Swing-out

The front of the trailer swings outward in the opposite direction of the turn; check mirrors before turning to avoid striking nearby objects or vehicles.

Total stopping distance

The sum of perception distance, reaction distance, brake lag distance, and effective braking distance; at highway speed it exceeds 300 feet for a loaded rig.

Backing toward driver side

Back the trailer toward the left side whenever possible so the driver can see the trailer in the left mirror; use a helper and small steering corrections.

Uncoupling sequence

Set trailer parking brakes, lower landing gear, disconnect glad hands and electrical cord, release fifth-wheel jaw, then pull tractor forward slowly and clear.

Coupling sequence

Chock wheels, align tractor, back under kingpin until jaws lock, tug test, connect air lines, raise landing gear, verify lights and brakes.

Glad hand connection

Connect the emergency (red) and service (blue) air lines to matching trailer couplers; cross-connection causes brake failure, so verify color matching.

Landing gear

The trailer support legs; raise fully before driving and lower to firm ground before uncoupling to prevent the trailer from tipping.

Skills test three parts

The CDL skills test consists of the pre-trip inspection, basic vehicle control, and on-road driving; all three must be passed to earn the license.

Pre-trip verbal inspection

The candidate must name each component, state what is being checked, and describe a defect; missing a critical item such as brakes or coupling fails the inspection.

Critical inspection items

Brakes, steering, coupling devices, tires, lights, and emergency equipment are critical; a defect in any of these fails the pre-trip inspection portion.

Straight-line backing

Back the rig in a straight line within the lane using mirrors; one pull-up is allowed, but crossing a boundary or hitting a cone is a deduction.

Offset backing

Back the trailer into an adjacent lane to the right or left while staying within boundaries; scored on setup, control, and final position.

Alley docking

Back into a simulated dock space and stop with the trailer straight and within the lines; striking the barrier or crossing lines is a deduction.

Automatic failure actions

Hitting a cone or boundary, causing an accident, failing to yield, running a stop sign or red light, or requiring examiner intervention fails the test.

Mirror use scoring

Examiners score continuous mirror checks during backing and lane changes; failure to monitor mirrors is a deduction on the road and control portions.

Range and splitter use

Manual-transmission candidates must demonstrate proper range shifting and splitter use without lugging, over-revving, or missing gears during the road test.

Railroad crossing procedure

Stop within 15 to 50 feet of the tracks, look and listen, and proceed only when clear; failing to stop when required fails the road test.

Bridge clearance check

Know the vehicle height and check posted clearance before passing under bridges or through tunnels; striking an overhead structure is an automatic failure.

Lane control scoring

Stay centered in the lane, signal before changes, and maintain speed; drifting, abrupt corrections, or unsignaled moves are deducted by the examiner.

Examiner intervention

Any action by the examiner to prevent an accident, such as grabbing the wheel or braking, results in automatic failure of the skills test.

Pre-trip point system

The inspection is scored on points; the candidate must identify all critical items and any unlisted critical defect fails the inspection portion.

Coupling demonstration

During the test, the candidate must show the full coupling sequence including tug test and jaw verification in the correct order without prompting.