There are online study guides, but the actual test has to be taken at their facility. On top of that, when you conduct your road test, you must take it in a vehicle appropriate to the class of license you're going for, and equipped with air brakes. Otherwise, you receive a "no air brakes" restriction on your CDL which prohibits you from operating a CMV equipped with air or air-over-hydraulic brakes.
The practice tests aren't really localized to states... unlike non-CDL licenses, CDLs are federally regulated, so what you're dealing with is going to be more the same across the entire United States. The CDL handbooks are pretty much all the same, as well, aside from the preface and matters pertaining to rules of the road for the state in question.
If you already have a CDL, you take the written air brakes test, then do a road test in a vehicle of the appropriate class which is equipped with air brakes.
There is tipically 5 questions an answers on the air brakes test in texas. Every other test except "genreal knowledge" test has 20 questions an answers. The genreal knowledge test has 50 questions an answers.
Take the written air brakes test, and perform a road test in a combination requiring a Class A CDL which is equipped with air brakes.
The air brakes portion of your CDL handbook.
You take the written Air Brakes test, and conduct your road test in a vehicle equipped with air brakes.
In Wyoming there are 20
You'll have to take the General Knowledge test, the Air Brakes test (if applicable), and the written test for the passenger endorsement. Additionally, for your road test, you'll be required to road test in a vehicle of the appropriate class and type (it must be a bus), and equipped with air brakes if you're trying to get air brakes on your CDL.
Yes there is a practice test for the CDL test online at www.freeassessmenttool.com/CDL. He may also want to check out the www.cdlstudy.com website first to elp him brush up on things before he takes the online test.
You can get a Class A CDL without air brakes - you'll just have a "no air brakes" restriction which prohibits you from operating a CMV equipped with air brakes. The vehicles you road test have to be commercial vehicles subject to FHWA regulations - recreational vehicles are exempt, so you cannot get a CDL with one.
There is no air brake endorsement. If you do not pass the written air brakes test AND complete your road test in a vehicle equipped with air brakes, then you get a restriction which prohibits you from operating an commercial vehicle which is equipped with air brakes. It is possible to have a Class A CDL with an air brake restriction.
The same as it would be otherwise, minus the air brakes written test.
You can get a free CDL air break practice test at www.testquestionsandanswers.com/cdl/air-brakes-test.html You could also try calling around local truck stops for help.