Offered autumn. Offered at Missoula College. Air brake design, construction, and operating principles including an in-depth study of diagnostic procedures for troubleshooting and repairing brake systems. Suspension systems and undercarriage design and repair are covered along with common axle alignment procedures found in industry. Students must complete this course with a letter grade of C or better to enroll in DST 225, Hydraulics in the second-half of the semester.