Workbook, Heavy Duty Truck Systems, 6E
Chapter Twenty-Nine – Answer Key
1. Which of the following components in a truck hydraulic brake system should have no
direct contact with the brake fluid?
2. Which of the following components would more likely be found in a split drum-and-disc
hydraulic brake system and not in a drum-only system?
3. Which component of a hydraulic brake system regulates pressure applied to the rear drum
brakes?
4. Which of the following describes the role of a hydraulic brake system load proportioning
valve?
5. Which of the following types of parking brakes would be most commonly used in an air-
over-hydraulic system?
6. When the term hygroscopic is used to describe a brake fluid, what does it mean?
7. Which of the following is a disadvantage of a hydraulic brake system when compared to
an air brake system?
8. In a dual-circuit hydraulic brake system, which of the following valves switches the brake
warning light in the event of severe fluid leakage in one of the circuits?
9. Which of the following hydraulic brake configurations would likely provide the highest
braking efficiencies on a two-axle straight truck chassis?
10. Which of the following is a disadvantage of disc brakes over drum brakes?