Questions and Answers
Glad hands are used to connect the?
Service and emergency air lines from the tractor to the trailer
Why should you be sure the fifth wheel plate is greased as required?
To prevent steering problems
After connecting the air lines, but before backing under the trailer, you should?
Supply air to the trailer system, then pull out the supply knob
A tractor trailer vehicle combination is most likely to roll over in a turn when the configuration includes?
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The trailer air supply control valve should automatically close when the air pressure falls to between what PSI?
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When coupling, the proper position of the fifth wheel is?
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Which part of the king pin should the locking jaws close around?
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When checking that the trailer is securely coupled to the tractor, the landing gear should be?
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A trailer is most likely to jackknife when it is?
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The spring doesn't release when you push the trailer air supply control valve; you should?
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Loss of air pressure in the emergency lines causes?
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When you get ready to back under a semi-trailer, you should line up?
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The best way to tell if your trailer has started to skid is to?
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Why should you lock the tractor glad hands to each other or to the dummy couplers when you are not towing a trailer?
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To unlock the fifth wheel, pull the release handle to the what position?
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When should you use the hand valve to park a combination vehicle?
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A driver crosses the air lines when hooking up to an old trailer; what will happen?
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You supply air to the trailer trucks by?
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The front trailer supports are up and the trailer is resting on the tractor; make sure?
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The safety latch for the fifth wheel locking lever must be and for a coupling to be correct?
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You are hooking a tractor to a semi-trailer and have backed up but are not under it; what should you do before backing under the trailer?
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After pushing in the trailer supply valve, you should not move the tractor until air system is?
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There are two things that a driver can do to prevent a rollover; they are one keep the cargo as close to the ground as possible and what else?
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With the engine off, and the brakes released and your foot on the brake pedal, a combination vehicle air brake system should not leak more than how many PSI in one minute?
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If the fifth wheel locking lever is not locked after the jaws close around the king pin?
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After coupling a semi-trailer you should crank the front trailer supports how high?
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Air brake equipped trailers made before 1975?
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During normal driving, some drivers use the trolly (hand valve) before the brake to prevent trailer skids. This should be done.
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You are hooking up to a tractor and semi-trailer and have connected both air lines; before backing under the trailer what should you do?
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If the service line disconnects while you are driving, what will happen right away?
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After hooking up you should check the fifth wheel connection by?
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When hooking a tractor to a trailer, you will know the trailer is at the correct height when the?
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You are driving a combination vehicle when the tractor breaks away and pulls apart the air lines; you would expect the trailer brakes to apply and?
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How much space should be between the upper and lower fifth wheel plates?
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At what angle do you connect your glad hand connections to the trailer?
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The hand valve should be used?
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What is off tracking?
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What is the purpose of the service lines?
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In coupling, when is the trailer height correct?
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Which of these statements about backing a vehicle is true?
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According to accident reports, the vehicle trucks and buses most often collide with is?
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Which of these is a good thing to do when steering to avoid a crash?
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For your safety when setting out reflective triangle, you should?
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You are dropping a trailer and the release arm won't release properly because the locking jaws have too much pressure on them; what should you do?
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If you are dropping a fully loaded trailer, how do you lower the landing gear?
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After unhooking tractor from trailer, pull tractor forward how far?
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After the tractor is pulled to the proper distance in front of the trailer, how do you secure the tractor?
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When inspecting the trailer supports, you should check for?
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If your trailer doesn't have spring brakes, how should you secure it?
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What color are the trailer service and emergency air lines?
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Study Notes
Glad Hands and Air Lines
- Glad hands connect service and emergency air lines from the tractor to the trailer.
- Trailer service air lines are colored blue; emergency air lines are red.
Fifth Wheel Maintenance
- Grease the fifth wheel plate to avoid steering issues.
- The proper fifth wheel position is tilted down toward the tractor's end.
Air System Procedures
- Supply air to the trailer system before backing under the trailer, then pull the supply knob.
- The trailer air supply control valve closes automatically when air pressure drops between 20 and 45 PSI.
- Avoid using the hand valve for parking; it should only be used to test trailer brakes.
Coupling and Coupling Safety
- Coupling is correct when the safety latch for the fifth wheel locking lever is over the lever.
- Before backing under a trailer, connect emergency and service air lines.
- The coupling device should be just below the middle of the tractor's fifth wheel to indicate proper trailer height.
Trailer Stability and Braking
- Triple 28-foot trailers are prone to rollovers, especially in turns.
- A trailer is likely to jackknife when it is empty.
- Loss of air pressure in emergency lines activates trailer brakes.
Driver Awareness and Safety
- Check fifth wheel connections by gently pulling the tractor ahead with the trailer brakes applied.
- Drivers should always see the trailer in mirrors to detect skidding.
- In the event of air line disconnection while driving, trailer brakes will engage only if the trailer has spring brakes.
Parking and Uncoupling a Trailer
- After unhooking from a trailer, pull the tractor forward until the rear tires align with the front of the trailer.
- When lowering landing gear on a fully loaded trailer, turn the crank a few extra turns after firm ground contact.
Safety Precautions
- Hold reflective triangles in a manner that positions you safely away from oncoming traffic.
- If the release arm won't disengage due to pressure on locking jaws, gently back up and set the tractor's brakes.
General Knowledge and Best Practices
- Maintain no gap between upper and lower fifth wheel plates during coupling.
- Off-tracking occurs when rear wheels follow a different path than the front.
- Turning should be minimal while steering to avoid collisions.
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Description
Test your knowledge on key terms and procedures related to combination vehicles in CDL training. From connecting air lines to maintaining the fifth wheel, these flashcards cover essential concepts for aspiring truck drivers. Perfect for preparing for your commercial driver's license exam!