Workbook, Heavy Duty Truck Systems, 6E
Chapter Twenty-Eight – Answer key
1. Technician A says that disc brakes use a steel rotor rotated at wheel speed that is
squeezed on either side by friction pads on a stationary caliper when actuated. Technician
B says that the clamping force exerted by the caliper in a pneumatic disc brake system is
delivered by an air brake chamber. Who is correct?
2. Of the following, which is not an advantage of using compressed air over hydraulic fluid
pressure?
3. Which of the following would be considered part of a truck service brake system?
4. Which type of air compressor would be most common on today’s heavy-duty trucks?
5. The spring brake system provides which of the following functions?
6. Which of the following service application valves can be referred to as a trolley valve?
7. Which of the following air brake system components could affect the pneumatic timing
of service applications?
8. Technician A says that the compressor crankcase contains the crankshaft, rod, and main
bearings. Technician B says that the compressor cylinder head assembly contains cam-
actuated discharge and inlet valves. Who is correct?
9. Which of the following is the most common means of supplying oil to a flange-mounted
air compressor?
10. Which of the following best describes the primary function of a tractor protection valve?