New Hampshire CDL DMV Endorsement Double 1

Most heavy-duty vehicles use dual air brake systems. A dual air brake system consists of two separate air brake systems, connected by a single set of brake controls. Each system has its own air tanks.

Wheels and rims with welding repairs are not safe to be used. Replace any damaged wheels and rims.

A large vehicle requires more space when entering or crossing traffic than a smaller vehicle. This is not only because the vehicle itself is larger, but also because it needs a longer distance to accelerate.

On a vehicle with ABS, a yellow malfunction lamp on the instrument panel will illuminate to alert you if the braking system is not working.

To avoid rolling over, you should drive slowly and steer gently when turning, taking curves, and driving around corners. Remember that a safe speed for a straight truck or single trailer combination may be too fast for a double or triple trailer combination.

When connecting a converter dolly to a second or third trailer, the trailer height should be correct. It should be slightly lower than the center of the fifth wheel.

When driving uphill, you are fighting the force of gravity, which will slow down your vehicle.

In the event of a vehicle fire, you should leave the road and stop in an open area. Do not pull into a service station as fuels at the service station could catch fire. Report the fire and your location to emergency services.

If you see, hear, smell, or feel anything while driving that does not feel right, you should have it checked out.

An air compressor governor will stop the compressor from pumping air once the air tanks are at an air pressure level of 125 psi. This air pressure level is referred to as the "cut-out" level.

Brakes out of adjustment will fade before those that are properly adjusted. Brake adjustment must be checked frequently to help prevent brake issues.

The function of an Anti-Lock Braking System (ABS) is to prevent a vehicle's wheels from locking up during hard braking.

The most common type of foundation brake is an s-cam drum brake.

The suspension system is responsible for supporting a vehicle, supporting its load, and keeping its axles in place. When inspecting your vehicle, check for damaged or missing spring hangers, spring leaves, shock absorbers, u-bolts, and frame members. Broken parts in the suspension system are extremely dangerous.

Drum brakes are attached to the wheels and located on the axles of a vehicle. The braking mechanisms that cause the vehicle to stop can be found inside of a drum brake.

Smoking, eating, or drinking are distracting activities and should be avoided while you are driving. Instead, plan ahead and allow yourself time to stop to eat when making a lengthy trip.

Pressing and releasing the brake pedal unnecessarily can let air out of the braking system faster than the compressor can replace it. Air brakes may cease to work effectively if the pressure becomes too low.

After starting a vehicle's engine, the oil pressure should come up to a normal level within seconds. Do not operate a vehicle if it has oil pressure that is low, dropping, or fluctuating.

When driving at dawn, at dusk, or in inclement weather, you should use your headlights on their low beam setting to increase your visibility.

If a tire fails, braking could cause a loss of control. Unless braking is necessary to avoid a hazard, you should stay off the brakes until your vehicle has slowed considerably. Only then should you brake very gently, pull off the road, and stop.