A freight driver starts the tractor unit and conducts a stationary check of dashboard inst… — Commercial Driver's License (CDL) General Knowledge Exam

A freight driver starts the tractor unit and conducts a stationary check of dashboard instruments, cabin controls, and safety gear. Which observed condition indicates an equipment defect that must be repaired before operating the vehicle?

A
The cabin safety kit contains three red reflective warning triangles, spare electrical fuses, and a charged $10\text{ B:C}$ fire extinguisher.
B
The oil pressure gauge starts near zero at engine crank and stabilizes within normal operating limits within $4\text{ seconds}$ of running.
The power steering wheel exhibits $20^\circ$ of free play (approximately $3.5\text{ inches}$ of movement on a $20\text{-inch}$ wheel) before the linkage turns the tires.Cevap
D
The dashboard voltmeter registers an electrical charging output of $14.1\text{ volts}$ while the engine idles.

Cevap

Power steering wheel free play measuring

20^\circ

(approximately

3.5\text{ inches}

on a

20\text{-inch}

steering wheel) before tire engagement is an unsafe defect that must be corrected.

Federal commercial vehicle safety regulations specify that power steering play must not exceed

10^\circ

, which corresponds to approximately

2\text{ inches}

of free movement on a standard

20\text{-inch}

steering wheel. A steering wheel exhibiting

20^\circ

of movement (or

3.5\text{ inches}

) before turning the wheels indicates excessive mechanical slack that degrades vehicle control and constitutes a mandatory repair defect.

Adım Adım Çözüm

Evaluate the mechanical steering play specification against federal inspection limits.

CDL regulations mandate that steering wheel free play on power steering systems must not exceed

10^\circ

, which equates to approximately

2\text{ inches}

of circumferential play on a standard

20\text{-inch}

steering wheel.

Steering play measuring

20^\circ

(or

3.5\text{ inches}

) exceeds legal limits and indicates worn steering linkages, universal joints, or a loose steering box.

Verify the operating parameters of the remaining in-cab indicators and emergency gear.

An oil pressure rise within

4\text{ seconds}

, a voltmeter output of

14.1\text{ volts}

, and an emergency kit with three red reflective triangles, fuses, and a

10\text{ B:C}

fire extinguisher all satisfy standard operational requirements.

Normal oil pressure builds within seconds of engine firing, charging voltage rests stably in the

13.5\text{ to }14.5\text{ volt}

range, and the emergency equipment list matches federal safety rules.

Anahtar Kavram

In-cab inspection standards for steering play tolerances, gauge stabilization, and mandatory emergency equipment.

Tahmini Süre:1m 0s

Soru

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Konular

Bu konudan daha fazla soru