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Safely pulling double and triple trailers requires knowledge and skill. If you want to pull double or triple trailers, you must add the Doubles/Triples (T) endorsement to your Class A CDL. The Massachusetts doubles triples test consists of 20 questions. To pass, you must correctly answer at least 16 questions (80%). The MA CDL doubles triples test covers the following sections of the Massachusetts CDL Manual: Driving Safely, Air Brakes (if you plan to operate vehicles equipped with air brakes), Combination Vehicles, Doubles and Triples. Take this MA CDL practice test now to prepare for the actual test!
1. Your vehicle has air brakes. To stop, you should:
push the brake pedal down.
pump the brake pedal 3 times.
release the accelerator, push in the clutch, and shift to Neutral at the same time.
pull the parking brake control knob out.
2. The center of gravity of a trailer should be:
as low as possible.
as high as possible.
at the rear of the trailer.
at the front of the trailer.
3. "Bobtail" tractors are:
tractors with two trailers.
heavily loaded trailers.
tractors without semitrailers.
tractors with a tank.
4. Under a pressurized system, the radiator cap:
should never be hot.
should never be removed until the system has cooled.
should be removed when the coolant is hot.
should always be cool.
5. Hanging meat in a refrigerated truck can be:
a very unstable load with a high center of gravity.
a very stable load if properly distributed.
a very stable load with a low center of gravity.
a very unstable load with a low center of gravity.
6. Regardless of its size, cargo should have at least ___ tie-downs.
7. When inspecting the coupling, how much space should there be between the upper and the lower fifth-wheel?
It depends on the load
It depends on the trailer
½ inch
8. For safety during a trip, you should:
watch gauges for signs of trouble.
check critical items when you stop.
use your senses to check for problems.
All of the above.
9. If your vehicle has air brakes, to check that air flows to all trailers:
watch each trailer’s air gauge for a drop of 25 psi.
go to the rear of the second trailer and open the emergency line shut-off.
check that the fifth wheel is not so far forward that the tractor frame will hit the landing gear.
pull gently on the trailer with the tractor.
10. No matter how small the cargo is, it should have at least:
6 tie-downs.
2 tie-downs.
4 tie-downs.
1 tie-down.
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MA CDL Doubles Triples Test

Number of questions: 20
Correct answers to pass:16
Passing score:80%
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