310T Preventive Maintenance and Inspection 2 — Questions and Answers
Question 1: What tool is used to measure brake lining thickness on a drum brake system during PM?
- Dial caliper or purpose-built lining gauge (Correct answer)
- Torque wrench
- Outside micrometer
- Feeler gauge
Correct answer: Dial caliper or purpose-built lining gauge
A dial caliper or lining gauge accurately measures the remaining friction material thickness to determine if linings are above the minimum serviceable limit.
Question 2: Which components are inspected to confirm the air dryer is functioning correctly during PM?
- Intake manifold pressure port
- Turbocharger wastegate actuator
- Purge valve operation and desiccant cartridge condition (Correct answer)
- Fuel filter housing drain
Correct answer: Purge valve operation and desiccant cartridge condition
A properly functioning air dryer expels moisture through the purge valve; checking purge valve operation and the desiccant cartridge confirms it is removing water from the air system.
Question 3: What does it indicate when a brake chamber push rod stroke exceeds the maximum allowable limit?
- The brakes are over-adjusted and applying too tightly
- The brakes are correctly adjusted
- The brakes are under-adjusted or excessively worn, reducing braking effectiveness (Correct answer)
- The push rod is too short and must be replaced
Correct answer: The brakes are under-adjusted or excessively worn, reducing braking effectiveness
Excess push rod stroke means the brakes require more travel to apply, indicating under-adjustment or worn linings that must be corrected immediately.
Question 4: What type of lubricant is typically specified for steering knuckle king pin bushings during chassis lubrication?
- Engine oil
- NLGI No. 2 multi-purpose lithium complex grease (Correct answer)
- Gear oil 80W-90
- Silicone spray lubricant
Correct answer: NLGI No. 2 multi-purpose lithium complex grease
NLGI No. 2 lithium complex grease provides the correct consistency and extreme-pressure protection required for high-load suspension and steering pivot points.
Question 5: During a belt inspection, which condition requires immediate replacement of a serpentine or V-belt?
- Light surface dust from normal operation
- Slight color change from aging
- Cracks, fraying, glazing, or missing chunks of material (Correct answer)
- A new belt that is slightly misaligned
Correct answer: Cracks, fraying, glazing, or missing chunks of material
Physical damage such as cracks, fraying, glazing, or missing chunks indicates the belt is near failure and could break without warning.
Question 6: What information must be documented on a vehicle inspection report (VIR) to maintain a complete maintenance record?
- Only parts that were replaced
- Driver's hours of service log
- Cargo manifest and load weights
- All defects found, repairs made, parts used, technician signature, and date (Correct answer)
Correct answer: All defects found, repairs made, parts used, technician signature, and date
A complete VIR documents every defect discovered, all corrective actions taken, parts installed, the technician's signature, and the date, creating a full auditable record.
Question 7: What is the purpose of the walk-around inspection portion of a commercial vehicle preventive maintenance check?
- To verify cargo securement only
- To systematically inspect the vehicle's exterior, tires, lights, and visible undercarriage components (Correct answer)
- To confirm driver licensing credentials
- To calculate fuel consumption per mile
Correct answer: To systematically inspect the vehicle's exterior, tires, lights, and visible undercarriage components
A structured walk-around ensures that exterior body, tires, lights, and undercarriage items visible during the circuit are checked in a consistent, repeatable sequence.
310T Preventive Maintenance and Inspection 2
What tool is used to measure brake lining thickness on a drum brake system during PM?