ND CDL General Knowledge flashcards

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

CDL Class A

A combination vehicle with a gross combination weight rating of 26,001 lb or more, provided the towed unit exceeds 10,000 lb. It permits operation of Class B and C vehicles as well.

CDL Class B

A single vehicle with a gross vehicle weight rating of 26,001 lb or more, or any such vehicle towing a unit of 10,000 lb or less. Includes Class C privileges.

CDL Class C

A single vehicle rated 26,000 lb or less that either carries 16 or more passengers or is used to haul placarded hazardous materials.

Pre-trip inspection sequence

Begin in the engine compartment checking fluids, belts, hoses, steering, exhaust, and leaks; then walk around checking lights and tires; finally test the brakes.

Total stopping distance

The sum of perception distance, reaction distance, brake lag distance, and braking distance. At 55 mph a loaded combination needs roughly a football field to stop.

Following distance rule

Below 40 mph, allow one second for each 10 feet of vehicle length plus one extra second. A 60-foot vehicle therefore needs seven seconds.

Downgrade gear selection

Choose a gear low enough that engine braking alone controls speed before starting down. Use brakes lightly and intermittently; never fan or ride them.

Railroad crossing stop

Stop within 15 to 50 feet of the nearest rail when driving a placarded hazmat vehicle, carrying passengers, or when a stop is posted. Never stop on the tracks.

CDL alcohol limit

A commercial driver is considered impaired at 0.04% blood alcohol concentration. Refusing a required test results in a one-year CDL disqualification.

Air buildup test

With the engine at fast idle, pressure must rise from 85 to 100 psi within 45 seconds. Slower buildup indicates a compressor or leak problem.

Low pressure warning

A warning buzzer or light must activate before air pressure falls below 60 psi. Below this level, braking performance is unsafe.

Governor cut-out pressure

The compressor stops pumping at roughly 120 to 140 psi and restarts about 20 to 25 psi lower. Failure to reach cut-out signals a faulty governor or compressor.

Static leakage limit

With the system fully charged and the engine off, pressure loss must not exceed 3 psi per minute for a single vehicle or 4 psi per minute for a combination.

Applied leakage limit

With the service brake fully applied and held, air loss must not exceed 4 psi per minute. Release the brake before performing other checks.

Spring brake application

Parking brakes are spring-applied and air-released. They engage automatically when pressure drops to roughly 20 to 45 psi, locking the wheels.

Safety valve setting

A valve on the air tank opens near 150 psi to release excess pressure. Venting during normal operation indicates a faulty governor or compressor.

Brake lag distance

The delay between pressing the pedal and the brakes applying at the wheels is about 0.4 second at 55 mph, adding roughly 32 feet to stopping distance.

Slack adjuster limit

Pushrod travel beyond the adjustment limit means the brakes are out of adjustment. The vehicle must be placed out of service until repaired.

Tractor protection valve

The red trailer air supply knob controls air to the trailer and closes automatically if the trailer breaks away, applying the trailer spring brakes.

Trailer hand valve

The johnson bar applies trailer brakes only. It is used for testing, never for parking or normal stopping, because it does not supply air to the trailer.

Tug test

After coupling, pull gently against the locked trailer brakes. If the trailer does not move, the kingpin is likely locked; then verify the jaws are closed.

Trailer air line colors

The emergency or supply line is red and the service line is blue. Reversed lines cause trailer brakes to stay applied or fail to release.

Off-tracking

Rear wheels of a combination follow a shorter path than the front wheels. In a 90-degree turn, a 55-foot trailer's rear can swing out about 5 feet.

Trailer swing-out

The rear of the trailer swings wide in the direction opposite the turn. Check both mirrors and the outside corner before starting a turn.

Combination brake test

With the trailer brakes released and the tractor brakes applied, the combination must not move. Then test the trailer brakes alone with the tractor released.

Coupling order

Secure the trailer, back under slowly, listen for the click, perform the tug test, connect the air lines and electrical cord, then raise the landing gear.

Placard weight threshold

Placards are required when 1,001 lb or more aggregate gross weight of one hazard class is loaded, or for any quantity of Table 2 materials.

Shipping paper order

The basic description lists the proper shipping name, hazard class or division, UN or NA identification number, and packing group in that sequence.

Emergency response information

This information must accompany the shipping paper and stay within the driver's reach, such as in a holder near the door, during transport.

Hazmat endorsement

The H endorsement requires a TSA security threat assessment. It is valid for the same period as the CDL and requires a new assessment at renewal.

Hazmat parking rules

Never park within 5 feet of a roadway. Stay at least 300 feet from open flames, bridges, tunnels, and heavily populated areas unless the shipper directs otherwise.

Fueling a placarded vehicle

The engine must be shut off during fueling, and smoking or open flames are prohibited within 25 feet of a placarded vehicle while loading, unloading, or stopped.