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Chapter 29
End of Chapter Review Questions Answer Key
1. In hydraulic disc brakes, the pads are forced against the rotors by:
2. As the pressure of fluid received by the wheel cylinder of a drum brake system
increases, which of the following happens?
3. Which of the following safety devices delays application of front disc brakes in a
disc/drum system until pressure is built up in the hydraulic system?
4. In a typical air-over-hydraulic brake system, depressing the treadle causes which of
the following?
5. Which of the following correctly describes the function of a load proportioning valve
(LPV) in an air-over-hydraulic system?
6. In a hydraulic brake system, brake fluid transmits any pressure applied:
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7. In a hydraulic brake system, which of the following best describes what happens
8. What component in a hydraulic brake system helps fluid in the master cylinder return
back to the reservoir after a brake application?
9. Technician A says that in non-servo drum brakes, the forward or leading shoe is
energized in normal braking when the vehicle is in forward motion. Technician B says
that in non-servo drum brakes, the leading and trailing shoes exchange roles when the
vehicle reverses motion. Who is correct?
10. In hydraulic drum brakes, the shoes are mechanically forced against the drums by:
11. A typical TIR specification for disc rotor lateral runout in a hydraulic brake system
would more likely be which of the following?
12. In a hydraulic drum brake system, what force pulls the shoes away from the drum
when the brakes are released?
13. Which of the following devices would play a role in illuminating the brake warning
light in the event of a complete hydraulic failure of the front brake circuit?
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14. A typical maximum rotor thickness variation specification required by an OEM would
likely be:
15. Technician A says that when replacing disc brake pads, most OEMs recommend that
fluid be removed from the master cylinder before compressing the caliper piston with
a C-clamp. Technician B says that the caliper bleed screw should be opened before
compressing a caliper piston with a C-clamp. Who is correct?
16. Which of the following best describes the electrical operation of a typical ABS wheel
speed sensor?
17. Which of the following components would
hydraulic ABS?
18. Which of the following would represent the typical maximum modulation cycle speed
of a hydraulic ABS?
19. Technician A says that an ABS ECU reads the frequency produced by a wheel speed
sensor and interprets it as wheel speed. Technician B says that the basis of hydraulic
ABS is that hydraulic pressure to the brakes over one wheel is relieved when a lockup
condition is sensed. Who is correct?
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20. Technician A says that when hydraulic ABS fails electronically, the system defaults
to normal hydraulic braking. Technician B says that a failure of one ABS wheel
sensor would result in a vehicle that should not be driven on the highway. Who is
correct?