Colorado CDL DMV Endorsement Double 2

To prevent rolling backward when starting from a stop, you should partly engage the clutch before removing your foot from the brake. Apply the parking brake whenever necessary to prevent your vehicle from rolling back.

If a vehicle is coming toward you while using its high beam headlights, glance away from the headlights and toward the right side of the road until the vehicle has passed. This will keep you from being blinded by the lights.

Most hydraulic brake failures occur for one of two reasons. A first likely cause of brake failure is that the brakes have been overused on a downgrade, causing them to fade. The second likely cause is that there has been a loss of hydraulic pressure in the braking system. Brakes kept in good condition will rarely fail, but you should know which steps to take in case they do.

All trailers and converter dollies manufactured on or after March 1, 1998 must be equipped with Anti-Lock Braking Systems (ABS).

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

Knowing proper coupling and uncoupling technique is fundamental to the safe operation of combination vehicles. Improper coupling can be very dangerous.

Potential problems to check for when inspecting brakes include cracked drums; shoes or pads with oil, grease, or brake fluid on them; and shoes that are missing, broken, or worn dangerously thin.

If you are unsure if a trailer is equipped with an Anti-Lock Braking System (ABS), look under the vehicle for the electronic control unit and wheel speed sensor wires coming from the back of the brakes.

If the air pressure warning light or buzzer comes on while you are driving, you should immediately stop and safely park the vehicle. This warning signal indicates that there is a problem in the air brake system that needs to be fixed.

If steering begins to feel heavy, it is likely that one of your front tires has failed. If you feel a change to your steering, you should exit the road as quickly as is safely possible and check your tires.

Accelerate smoothly and gradually. Rough acceleration can cause mechanical damage.

If you must stop and park on the side of the road, make sure to turn on your emergency flashers. This is especially important at night. Taillights are not an adequate when alerting other drivers because the drivers may mistakenly think your vehicle is moving normally and collide with it.

Railroad-highway crossings may be difficult to cross when pulling a trailer with a low underneath clearance. In particular, both low-slung units and single-axle tractors pulling long trailers are especially challenging to drive over raised crossings.

The trailer hand valve should not be used for parking. This could cause all of the air to leak out of the braking system, resulting in the brakes releasing. Instead, use the parking brake.

When performing a static leakage test on a triple combination vehicle with air brakes, the leakage rate should be no more than 5 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.

Double and triple trailers are less stable than single commercial vehicles and are more likely to roll over when being driven. To prevent rollovers, doubles and triples must be driven very smoothly and gently.

In an air brake system, pressing and releasing the brake pedal unnecessarily can release air from the braking system faster than the compressor can replace it.

All commercial motor vehicles are required to be equipped with the proper emergency equipment. This may include spare electrical fuses; three red reflective triangles, six fuses, or three liquid burning flares; and at least one properly charged and rated fire extinguisher.

Hydroplaning is most likely to occur on wet roads if tire pressure is low or if tire tread is worn. If there is enough water on the road, hydroplaning can occur at speeds as low as 30 mph.

Driving a combination vehicle usually requires more skill than driving a single vehicle. Combination vehicles are generally longer and heavier than single commercial vehicles.