Massachusetts CDL DMV Endorsement Double 1

Always apply the parking brake when leaving your vehicle.

Most heavy-duty vehicles use dual air brake systems. A dual system has two separate air brake systems with a single set of controls.

After a trip, you may be required to perform an inspection and file a report on each vehicle that you've driven.

If your vehicle "pulls" to one side when braking, you may have brake trouble. If there is an issue with your brakes, you should fix the issue before driving. Operating an unsafe vehicle is against federal and state laws.

If a trailer begins to jackknife, you should release the brakes and allow the trailer wheels to regain traction with the road. Do not apply the trailer hand brake in an attempt to straighten out the rig because it will only prolong the skid. The application of brakes is what caused the wheels to lock in the first place.

Large vehicles often have curved, convex mirrors, sometimes referred to as "fisheye," "spot," or "bug-eye" mirrors. These mirrors provide a wider view than flat mirrors. However, they also make objects seem smaller and farther away than they actually are.

To lower the risk of a rollover, load your cargo as closely to the ground as possible. To further reduce this risk, take curves and corners slowly.

Driving while fatigued is dangerous. Warning signs of fatigue include difficulty focusing; repeated yawning or rubbing of the eyes; daydreaming or wandering thoughts; and drifting out of your lane.

When driving a tractor-trailer combination equipped with an Anti-Lock Braking System (ABS), you should brake in the same manner that you would if operating a vehicle without ABS.

When performing a static leakage test on a double combination vehicle with air brakes, the leakage rate should be no more than 3 psi in one minute. If air leaks from the air brake system at a quicker rate, the vehicle should not be driven because something likely needs to be repaired.

Slow down and be very careful if you see foreign objects in your lane. Remember that even something that seems relatively light and harmless, like a cardboard box, could contain harder or heavier items that could cause damage to your vehicle.

The stab braking method for emergency stops involves fully applying the brakes until they lock up. The brakes are then released until the wheels start rolling, and then the process is repeated.

After a vehicle's engine is started, the engine's oil pressure should rise to its normal level within seconds. Do not drive a vehicle with oil pressure that is too low.

While driving, you should consistently check the road ahead for hazards. Develop a plan to deal with any hazards that could arise.

To reduce the risk of distraction, do not engage in complex or emotionally intense conversations while driving. Pre-programming radio stations before your trip and avoiding eating, drinking, or smoking while at the wheel can also help you avoid becoming distracted while driving. Remember that mental distractions that take your attention away from the task of driving can be just as dangerous as physical distractions.

In an air brake system, the air storage tanks are equipped with drains to allow water and compressor oil to be removed. The water and oil can damage the brakes if left to accumulate in the system.

At the end of each day of driving, you may be required to make a written report on the vehicle or vehicles driven. Be sure to make note of any issues that could affect the safety of the vehicle or that could lead to a mechanical breakdown.

A broken exhaust system can allow poisonous fumes to enter a vehicle's cab or sleeper berth. Be sure to regularly check your exhaust system for defects.

You can build up a "debt" of sleep if you do not sleep for adequate amounts of time. You can only catch up on the time that you "owe" by getting more sleep.

A low air pressure warning signal is required in vehicles with air brakes. The warning light is usually red and may be accompanied by a buzzer.