Examination Practice Questions And

Illinois Fleet Mechanic Certification Examination Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What is the primary purpose of a vehicle’s cooling system?
• Reduce engine noise
• Maintain optimal engine temperature
• Increase fuel efficiency
• Control exhaust emissions
• Maintain optimal engine temperature

Rationale: The cooling system removes excess heat from the engine

to prevent overheating and ensure proper operation.

• Which tool is used to measure the thickness of brake rotors?
• Caliper 1 / 4

• Micrometer
• Torque wrench
• Feeler gauge
• Micrometer

Rationale: A micrometer provides precise measurements of brake

rotor thickness to ensure safety and proper brake function.

• What type of oil is typically recommended for modern diesel engines?
• SAE 10W-30 gasoline oil
• SAE 15W-40 diesel oil
• SAE 5W-20 gasoline oil
• Non-detergent oil
• SAE 15W-40 diesel oil

Rationale: Diesel engines require heavier, high-temperature oil with

detergents to handle soot and high compression conditions.

• A vehicle has a hard starting problem in cold weather. Which

component is most likely at fault?

• Fuel pump
• Battery
• Alternator
• Radiator
• Battery

Rationale: Cold weather reduces battery efficiency, and a weak

battery may not provide sufficient cranking power. 2 / 4

• Which brake system uses hydraulic pressure to operate the brakes?
• Air brakes
• Hydraulic brakes
• Mechanical brakes
• Vacuum brakes
• Hydraulic brakes

Rationale: Hydraulic brakes transmit force through brake fluid,

providing consistent braking pressure.

• What is the function of a vehicle’s alternator?
• Store electrical energy
• Convert mechanical energy to electrical energy
• Control fuel injection
• Increase engine compression
• Convert mechanical energy to electrical energy

Rationale: The alternator charges the battery and powers electrical

systems while the engine is running.

• When performing a tire rotation, which pattern is commonly

recommended for front-wheel drive vehicles?

• Rearward cross
• Forward cross
• X-pattern
• Side-to-side only
• Forward cross 3 / 4

Rationale: The forward cross pattern helps even out tire wear on

front-wheel-drive vehicles.

• Which type of transmission fluid is typically used in automatic

transmissions?

• Dexron/Mercon

B. SAE 10W-30

• Gear oil
• Engine coolant
• Dexron/Mercon

Rationale: Automatic transmissions require specialized fluids like

Dexron or Mercon to provide lubrication and hydraulic function.

• What is the primary function of the vehicle’s suspension system?
• Provide vehicle acceleration
• Support vehicle weight and absorb shocks
• Control brake operation
• Maintain engine temperature
• Support vehicle weight and absorb shocks

Rationale: The suspension system ensures a smooth ride and

maintains tire contact with the road.

• Which instrument measures engine revolutions per minute

(RPM)?

• Tachometer
• Speedometer
• / 4