69. What is the purpose of an alcohol evaporator?
Detailed Explanation
The correct answer is "To reduce the risk of ice in the brake valves and other parts in cold weather.". This question tests driver fitness and recognizing conditions that make commercial driving unsafe. For a differently worded version of this question, identify the hazard first and then choose the answer that preserves control, visibility, or legal compliance.
Correct Answer: To reduce the risk of ice in the brake valves and other parts in cold weather.
Why This Matters on the CDL Test
Use this as part of your Air Brakes review. The real CDL knowledge test rewards drivers who understand the reason behind each rule, not only the answer letter, so read the explanation and then try a few related questions.
How to Remember It
Say the rule in your own words, then explain why the wrong answers are unsafe or incomplete. That habit makes similar Air Brakes questions easier when the exam changes the wording.
Answer Review
Choose "To reduce the risk of ice in the brake valves and other parts in cold weather." because this answer matches the safe CDL action for air brakes knowledge. On the knowledge test, the safest answer is usually the one that protects space, control, visibility, legal compliance, or inspection accuracy before the vehicle is put at risk.
Why the other answers are weaker
- So you don't have to drain the air tanks as often."So you don't have to drain the air tanks as often." does not best answer this air brakes knowledge question. When you see a similar option on the CDL permit test, compare it against the exact safety rule and choose the answer that prevents the most immediate risk.
- To have a drink available if you get thirsty."To have a drink available if you get thirsty." does not best answer this air brakes knowledge question. When you see a similar option on the CDL permit test, compare it against the exact safety rule and choose the answer that prevents the most immediate risk.
Test-Day Checklist
- Read the question once for the topic, then read it again for the exact CDL action being tested in Air Brakes.
- Eliminate answers that sound convenient but skip an inspection, warning sign, or safety step.
- Say the correct rule out loud before moving on so you can recognize it when the exam changes the wording.
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Start Practice TestRelated Questions
108. If your vehicle has an alcohol evaporator, it is there to:
72. If your vehicle has an alcohol evaporator you should check and fill the alcohol level everyday during cold weather.
92. Some air brake systems have an alcohol evaporator. What may happen if you don't keep the unit filled with alcohol?
99. If your vehicle has an alcohol evaporator, everyday during cold weather you should:
In cold weather, an alcohol evaporator should be checked and filled:
Keep Studying Air Brakes
Question pages help you review one rule at a time. To build test-day speed, move back into the full Air Brakes practice test and answer a mixed set without looking at the explanation first.
State CDL Practice Paths
After you understand this answer, use a state practice path to connect the federal CDL rule with the DMV test pages drivers search for most.