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Difficulty: MediumBrake Failure

If brake fade begins during a descent, applying harder foot pressure on the service brake pedal will compensate for expanding brake drums and restore normal stopping power.

Answer: Answer

Answer

False
The statement is false because excessive heat changes the chemical structure of the brake linings and expands the brake drums away from the shoes. Increasing pedal pressure creates even more heat, worsening drum expansion and lining glaze until braking force is completely lost.

Step-by-Step Solution

1
Analyze the physical cause of thermal brake fade during downhill operation.
Excessive braking generates extreme heat that alters the chemical composition of the friction linings and causes brake drums to expand radially outward.
Understanding the mechanical and thermal limitations of drum brakes is critical for diagnosing brake failure.
2
Evaluate the effect of increasing brake pedal application pressure during an active fade condition.
Applying additional pedal pressure increases friction heat exponentially, driving drum expansion further outward and accelerating lining glazing.
Pushing harder cannot overcome the physical expansion gap and loss of friction coefficient once thermal fade has commenced.
3
Determine the truth value of the statement.
The statement is false because increased application pressure aggravates brake fade rather than restoring stopping power.
Proper response to brake fade requires using engine braking, downshifting before the grade, or taking an escape route rather than over-applying failing service brakes.

Key Concept

Thermal Brake Fade and Drum Expansion
Estimated Time:1m 0s
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Topics

Brake Failure

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