California CDL air brakes practice test
25 questions marked at 20 to pass, which is the federal 80 percent standard set by 49 CFR 383.135. CDL knowledge is federal, so this test is the same wherever you sit it. Every answer cites the law behind it. No signup, no email.
25 questions, 40 minutes. The timer starts when you begin, and answers are shown at the end.
About the time limit
This paper allows 40 minutes, and that allowance is ours rather than a federal rule. We could not find a published time limit for this test, and in practice US knowledge tests are usually not run against a strict clock at a service center. The timer is here so the practice feels like a real sitting, not because the real one ends at 40 minutes.
Where these questions come from
This paper draws 0 California-specific questions written from that state's own statutes and official handbook, together with 25 on rules that do not vary between states. They are original questions written from the rules themselves, not the examination questions California DMV uses. This site is not affiliated with or endorsed by California DMV.
More California practice: car and motorcycle and truck (cdl) and cdl combination, or the California test guide.