Combination Vehicles CDL Practice Questions
62 free Combination Vehicles CDL-style practice questions.
Before you back under a trailer, make sure that:You are coupling a tractor to a semitrailer and have backed up, but are not under it. What should you…The air brake leakage rate for a combination vehicle (engine off, brakes off) should not be more than ____ psi…Your emergency air line breaks or gets pulled apart while you are driving. The loss of pressure will cause the:If the service line comes apart while you are driving a combination vehicle, but the emergency line stays together, what…Why should you be sure that the fifth wheel plate is greased as required?After you supply air to the trailer, make sure the air lines are not crossed and the trailer brakes are…The fifth wheel locking lever is not locked after the jaws close around the kingpin. This means that:The safety latch for the fifth wheel locking lever must be _____ for a coupling to be complete.A tractor with a _______ trailer requires the most amount of stopping distance.To unlock the fifth wheel, the locking lever should be placed in the ______ position.You have pushed the trailer air supply valve. You should not back a tractor under a trailer until the whole…When uncoupling the trailer, after you shut off the trailer air supply and lock the trailer brakes, you should:You have coupled with a semitrailer, where should you put the iron trailer supports before driving away?There are two things that a driver can do to prevent a rollover: They are: (1) go slow around turns,…You are driving a combination vehicle when the trailer breaks away, pulling apart both air lines. You expect the trailer…The air lines on a combination vehicle are often colored to prevent them from mixing up. The emergency line is…What will happen if the air lines are crossed when you hook up to an old trailer?After the trailer has been coupled to the tractor, the tractor protection control valve should be placed in what position?While checking if the trailer is securely coupled to the tractor, the landing gears should be:If the spring brakes are not released when you push the trailer air supply valve, you should:Glad hands are usually connecting which of these?How much space should be allowed between the upper and lower fifth wheel after coupling?You have a major leak in the service line, and you put on the brakes. Service air will escape and…Semi-trailers made before 1975 that are equipped with air brakes:To stop a trailer skid, you should:You supply air to the trailer tanks by:What gear should the tractor engine be in after you uncouple the trailer and are inspecting the trailer supports?When coupling, the proper position of the fifth wheel is:When connecting the glad hands, press the two seals with the couplers together at what degree to each other?Your emergency air line breaks or gets pulled apart while you are driving. The loss of pressure will cause the:There are two things that a driver can do to prevent a rollover. They are: (1) go slow around turns,…The higher the center of gravity of your truck, the:The air leakage rate for a combination vehicle (engine off, brakes on) should not be more than _____ psi per…You should not back a tractor under a trailer until the air system is:You are about to back your tractor under a semitrailer. The trailer is at the right height when the:After connecting the air lines but before backing under the trailer, you should:How should you test the tractor-semitrailer connection for security?Air and electrical lines from the tractor to the trailer should be:After you lock the kingpin into the fifth wheel, you should check the connection by:Off-tracking or cheating causes which of these to follow the wider path while making a turn?Compared to a straight truck or bus, there are ______ things to inspect in combination vehicles.When driving a set of doubles, it is necessary to close which shut-off valve in the last trailer:You are coupling a tractor to the semitrailer; you have connected the airlines. Before backing under the trailer, you should:Air brake-equipped trailers made before 1975:Why should you lock the tractor's glad hands to each other (or dummy couplers) when you are not towing a…In normal driving, some drivers use the hand valve before the brake pedal to prevent a jack-knife. Which of the…The hand valve should be used:The front trailer supports are up, and the trailer is resting on the tractor. Make sure:A driver crosses the air lines when hooking up to an old trailer. What will happen?
Page 1 of 2Next →