Directions: This endorsement is required for driving a vehicle with air brakes. To receive this endorsement, applicants must pass a written test. The test consists of 25 multiple choice questions. Each question has three or four answer choices. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the Montana Commercial Driver License Manual. Questions come from the chapter covering: Air Brakes. The Air Brakes endorsement may be used with the Class A, B or C CDL.

When tank pressure falls below 120 psi.
When tank pressure falls below 60 psi.
When tank pressure falls below 10 psi.
When tank pressure falls below 5 psi.

Orange
Yellow
Green
Blue

Two minutes.
15 seconds.
10 minutes.
45 seconds.

Montana CDL Permit Test - Air Brakes

A low air pressure warning signal should activate:

What color are ABS malfunction lamps?

Anti-Lock Braking Systems (ABS):

What kind of brakes do most newer heavy-duty trucks use?

During an inspection, slack adjusters on S-cam brakes should not move more than:

The air pressure in a dual air brake system should build from 85 to 100 psi within:

Number of questions:	25
Passing score:	20

Reduce a vehicle's normal braking capacity.
Are in addition to other braking systems and do not reduce a vehicle's braking power.
Are not effective on larger vehicles.

One foot.
One centimeter.
One inch.