CDL Class A License Test 1 Flashcards

You supply air to the trailer tanks by?

A driver crosses the air lines when hooking up to an old trailer with no spring brakes. What will happen?

Gland hands are used to connect the:

After you connect the air lines, but before you back under the trailer, you should?

To unlock the fifth wheel pull the release handle to the______ position.

For a coupling to be complete, the safety catch for the fifth wheel locking lever must be?

Which part of the kingpin should the locking jaws close around?

Why should you be sure that the fifth wheel plate is greased as required?

When should you use the hand valve to park a combination vehicle?

The trailer air supply should automatically close when the air pressure falls to between_____ Psi.

The best way to tell if your trailer has started to skid is to?

When coupling, the proper position of the fifth wheel is?

A trailer is most likely to jackknife when it is?

If the spring brakes don't release when you push the trailer air supply control, you should?

The front trailer supports are up and the trailer is resting on the tractor; make sure?

Total stopping distance for vehicles with air brakes is longer than that for vehicles with hydraulic brakes due to______ distance.

Some air brake systems have an alcohol evaporator. What may happen if you don't keep the unit filled with alcohol?

What is emergency stab braking?

Air is supplied to the trailer tanks by pushing in the trailer air supply valve.
When air lines are crossed during hookup to an old trailer without spring brakes, the driver could end up driving away without trailer brakes.
Gland hands are used to connect service and emergency air lines from the truck to the trailer.

After connecting air lines but before backing under the trailer, supply air to the trailer system and then pull the air supply knob.

To unlock the fifth wheel, pull the release handle to the open position.
For a complete coupling, ensure the safety catch for the fifth wheel locking lever is over the locking lever.
The locking jaws should close around the head of the kingpin, referred to as "the shark".

Greasing the fifth wheel plate prevents steering problems.
The hand valve should never be used to park a combination vehicle.
The trailer air supply automatically closes when air pressure falls between 20 and 45 PSI.

The best way to detect if a trailer has started to skid is by observing it in your mirrors.
During coupling, the fifth wheel should be tilted down towards the end of the tractor.
A trailer is most likely to jackknife when it is empty.

If spring brakes do not release after pushing the trailer air supply control, check the air connection lines.
Ensure there is enough clearance between the tractor frame and landing gear when the trailer is resting on the tractor.
Air brake vehicles experience longer total stopping distances due to brake lag.

In air brake systems with an alcohol evaporator, lack of alcohol could lead to ice formation in air storage tanks, causing brake failure.
Emergency stab braking involves braking hard, releasing once the wheels lock, and reapplying when they start rolling.