# Free Florida CDL Combination Vehicles Practice Test 2023

Our CDL practice tests:
Based on 2021 FL commercial driver's license manual
Perfect for first-time, renewal applicants
FL CDL Combination Vehicles Test format:
20 questions
80% passing score
List of questions
1.
After supplying air to the trailer, how should you check for crossed air lines?
2.
The trailer air supply control knob is _____.
3.
While driving behind another vehicle, under good conditions, you should allow at least one second between your vehicle and the vehicle ahead for each ____ feet of your vehicle length.
4.
The air leakage rate for a combination vehicle (engine off, brakes on) should not be more than _____ psi per minute.
5.
You have pushed the trailer air supply valve. You should not back a tractor under a trailer until the whole air system is:
6.
Off-tracking or cheating causes which of these to follow the wider path while making a turn?
7.
There are two things that a driver can do to prevent a rollover. They are: (1) go slow around turns, and (2):
8.
A major leak in the trailer emergency line will cause:
9.
The emergency air line controls the emergency brakes on combination vehicles, and:
10.
A driver crosses the air lines when hooking up to an old trailer. What will happen?
11.
When unlocking the fifth wheel in Step 6, all of the following apply, EXCEPT:
12.
If the wheels of the trailer lock up and the trailer swings around, it could cause a:
13.
When uncoupling, the tractor should:
14.
Converter dollies:
15.
You are about to back your tractor under a semitrailer. The trailer is at the right height when the:
16.
The safety latch for the fifth wheel locking lever must be _____ for a coupling to be complete.
17.
The hand valve should be used:
18.
Where should the tractor be when you inspect the landing gear after uncoupling the trailer?
19.
Why should you lock the tractor glad hands to each other (or dummy couplers) when you are not towing a trailer?
20.
In case of landing gear failure while pulling out from under it, you should: