MA Modernized Class B 10 Step Air Brakes Test - Compounding Brakes Explained

Compounding Brakes is an automatic failure when going for your Class B State Road Test.

This video explains what Compounding Brakes means for those who are unaware. Some vehicles have interlocking braking systems that REQUIRE you to compound Brakes. If your vehicle is equipped with such a feature, you MUST notify the examiner at the beginning of your test. Failure to do so will result in an automatic failure.

Please comment if unclear of Compounding Brakes.

Also, you may notice the Cut Out range changed from 120-125 PSI and is now a range of 120-140 PSI. That range must now be stated.

For Applied Air Pressure test, you must state you are applying and holding 90 pounds of pressure to the Service Brake. If you vehicle does not have an Air Pressure SUPPLY gauge, you will simply press the Service Brake Pedal to the ground.

Also changed is the Low Air Pressure range. It was previously 60 PSI, Now you must state "on or before 55 PSI"