CDL Class B - Doubles and Triples
Terms in this set (40)
True or false? Converter dollies built on or after March 1, 1998, are required to have antilock brakes.
Converter dollies with antilock brakes will have a ______ stamp on the _______ side of the dolly.
When coupling a twin trailer, the first step is to:
Secure the second (rear) trailer
When coupling twin trailers, the more heavily loaded semitrailer should be:
In the first position behind the tractor
When connecting a converter dolly to the rear trailer, make sure that the trailer brakes are ___________ and/or the wheels are __________.
When positioning the converter dolly in front of a second (rear) trailer, you can release the dolly brakes by opening the:
Air tank petcock
When uncoupling twin trailers, the first thing you should do is:
Uncouple the rear trailer
When uncoupling the rear trailer of twin trailers, you will need to chock the wheels of ______________ trailer if it doesn't have spring brakes.
True or false? When uncoupling the converter dolly of twin trailers, it is acceptable to unlock the pintle hook with the dolly under the rear trailer.
When coupling triple trailers, start by coupling the _________ to the _____________.
Tractor, first trailer.
When inspecting double and triple trailers, make sure that there is no visible space between the upper and lower ____________.
When checking double and triple trailers, the rear of the front trailers should be ___________, the rear of the last trailer should be ____________, and the converter dolly air tank drain valve should be ______________.
Open, closed, closed.
When checking double and triple trailers, be sure that the pintle-eye of the dolly is in place in the ___________ of the trailers.
For double and triple trailers, you will need to check that air flows to all of the trailers. To do this, you will need to use the ______________ to provide air to the service line.
When you test the emergency brakes for double and triple trailers, the first step will be to:
Charge the trailer air brake system
When parking a double or triple trailer, make sure that you will be able to:
Pull straight through
What is a converter dolly used for?
To couple two or three trailers behind a tractor truck
Do all converter dollies have spring brakes?
True or false? The dolly tow bar may fly up if you unlock the pintle hook with the converter dolly still under the rear trailer.
True or false? You should use different methods for uncoupling second and third trailers.
What is a converter gear or dolly?
A coupling device of one or two axles and a fifth wheel by which a semi-trailer can be coupled to the rear of a tractor-trailer combination forming a double bottom ring.
Do converter dollies have spring brakes?
They may or may not
Before coupling, what do you need to do regarding trailer height?
Make sure trailer height is correct. (It must be slightly lower than the center of the fifth wheel, so trailer is raised slightly when dolly is pushed under)
What do you check when making a visual check of coupling?
Check to make sure there is no space between upper and lower fifth wheel. Locking jaws closed on kingpin.
Why should you pull a dolly out from under a trailer before you disconnect it from the trailer in front?
The dolly tow bar may fly up, possibly causing injury, and making it very difficult to re-couple.
When coupling twin trailers, you should release the dolly brakes by:
Opening the air tank petcock
When connecting the converter dolly to the rear trailer, you should remember to:
-Make sure trailer brakes are locked
-Make sure trailer height is correct
-Raise the landing gear slightly off the ground
When coupling the rear trailer, the correct trailer height is:
Slightly lower than the fifth wheel
To uncouple the converter dolly, you should:
Lower the landing gear, disconnect safety chains, and chock the wheels
When inspecting doubles, the shut off valves at the rear of the trailer should be:
Open at the rear of the front trailer, closed at the rear of the last trailer
To check for air flow to the last trailer:
Open emergency shut off valve and listen for escaping air
What is a converter dolly?
A coupling device of one or two axles and a fifth wheel by which a semi-trailer can be coupled to the rear of a tractor-trailer combination forming a double bottom rig.
Since a sudden movement with your steering wheel can tip a trailer over, how far behind other vehicles should you follow when pulling trailers?
At least one second for each ten feet of your vehicle length, plus another second if going over 40 miles per hour.
Why do large combination vehicles that are empty take longer to stop than when they are fully loaded?
When lightly loaded, still suspension springs and strong brakes give poor traction and make it easy to lock up the wheels.
What is a reason why there is a higher chance of skids with doubles and triples in bad weather, slippery conditions and mountain driving?
You have more length and more dead axles to pull.
In normal driving, should you ever use the trailer hand valve before the brake pedal to prevent trailer skids?
Which valve keeps air in the tractor or truck if the trailer breaks away or develops a bad leak?
The tractor protection valve
Which valves on the service line on the trailer connects the trailer air tanks to the trailer air brakes?
Why should you lock the glad hands to each other when you are not towing any trailers?
To keep water and dirt out of the lines
If the spring brakes do not release when you push the trailer air supply control, what should you do?
Check the air line connections