New Mexico CDL General Knowledge flashcards
New Mexico CDL General Knowledge · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Total stopping distance
- The sum of perception distance, reaction distance, brake lag distance, and braking distance. At 55 mph a loaded tractor-trailer needs about the length of a football field to stop.
- Following distance rule
- Allow at least one second per 10 feet of vehicle length below 40 mph, plus one second above 40 mph. A 60-foot rig at 55 mph needs 7 seconds.
- Brake lag distance
- The distance traveled while air pressure moves through the lines to apply the brakes, about 32 feet at 55 mph. This is why air brakes stop slower than hydraulic brakes.
- Hydroplaning
- Tires ride on a layer of water and lose contact with the road. It happens at speeds as low as 30 mph, and the best response is to slow down and avoid hard braking.
- Aggregate working load limit
- The total strength of all tiedowns used to secure cargo. It must equal at least 50 percent of the weight of the cargo being secured.
- Tiedown count rule
- One tiedown for articles 5 feet or less and 1,100 lb or less; two for longer articles up to 1,100 lb; three for articles over 5 feet or over 1,100 lb.
- Rear overhang flag
- Cargo extending more than 4 feet beyond the rear of the vehicle must display a red flag at least 12 inches square in daylight and a red light at night.
- Cargo securement check
- Inspect cargo and tiedowns within the first 50 miles of a trip and again after 150 miles or 3 hours of driving, whichever comes first.
- Air brake buildup test
- With the engine at fast idle, pressure must build from 85 to 100 psi in 45 seconds or less. A slower buildup points to a leak or weak compressor.
- Low-air warning
- The buzzer and light must come on before pressure drops below 60 psi. The spring brakes must fully apply between 20 and 45 psi.
- Safety valve setting
- The air brake safety valve must open at 150 psi. If it opens at a lower pressure, the system needs service before the vehicle is driven.
- Leak rate test
- With the engine off and brakes released, loss must not exceed 3 psi per minute for a single vehicle or 4 psi for a combination; with brakes applied, 4 or 6 psi.
- Tug test
- After coupling, set the trailer brakes, put the tractor in a low gear, and pull gently. If the trailer moves, the fifth wheel is not locked.
- Tractor protection valve
- A valve that keeps air in the tractor if a trailer breaks away or an air line is cut, allowing the tractor to stop safely.
- Trailer hand valve
- The trolley valve on the steering column. It should be used only to test the trailer brakes, never to park or hold the vehicle.
- Off-tracking
- The tendency of the rear wheels of a combination to follow a shorter path than the front wheels. Swing wide and check mirrors before turning.
- Converter dolly
- A separate axle with a fifth wheel and a drawbar that connects a second or third trailer to the tractor, with its own air and electrical lines.
- Rear trailer shut-off valve
- The last trailer in a double or triple must have a shut-off valve on its emergency air line at the rear; the front trailer does not.
- Liquid surge
- The movement of liquid inside a partially filled tank. Baffles slow the surge, and a tank without baffles is safest when nearly full or nearly empty.
- Baffles
- Dividers inside a tank that slow the movement of liquid. Damaged or missing baffles allow uncontrolled surge and increase rollover risk.
- Grounding and bonding
- Connecting the tank and the receiving container to each other and to the ground during loading or unloading of flammable liquids, to prevent static ignition.
- Hazmat placard threshold
- Placards are required for 1,001 lb or more of a hazard class in one vehicle, for any amount of a Table 2 material, and for any amount of a Table 1 material.
- Shipping paper contents
- The paper must show the proper shipping name, hazard class, identification number, total quantity, and shipper's certification, plus emergency response information.
- Hazmat parking rule
- Never park a placarded vehicle within 5 feet of a roadway, and never within 300 feet of an open flame or a bridge or tunnel.
- School bus 8-light system
- Amber lights flash at least 100 feet before the stop. Red lights and the stop arm deploy when the bus is stopped to load or unload students.
- School bus railroad stop
- Stop at least 15 feet but not more than 50 feet from the nearest rail, open the door, and listen before crossing the tracks.
- School bus student check
- Walk to the back of the bus after every route and every trip to confirm no student remains on board. Never refuel with students aboard.
- Brake slack adjuster check
- The slack adjuster should not move more than 1 inch by hand at the push rod, and the push rod should not travel more than 2 inches.
- Tire tread minimums
- At least 4/32 inch on front steering tires and 2/32 inch on all other tires. Check for cuts, bulges, and recaps during the walk-around.
- Driver vehicle inspection report
- A written report of any defect found during the post-trip inspection. The carrier must repair the defect before the vehicle is used again.
- GOAL
- Get Out And Look. When backing without a helper, stop, get out, and check the area behind the vehicle before continuing to back.
- Double clutching
- Pressing the clutch, shifting to neutral, releasing the clutch, pressing it again, and shifting into the next gear. Used when the transmission is not synchronized.