Yukon Heavy Equipment Technician
Certification Exam Questions And Correct
Answers (Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. What is the primary purpose of a torque converter in an
automatic transmission?
a) To increase engine horsepower
b) To allow the engine to continue running while the vehicle is
stationary
c) To reduce fuel consumption
d) To control vehicle steering
b) To allow the engine to continue running while the vehicle is
stationary
The torque converter transmits engine power to the transmission
while allowing the engine to idle without stalling.
2. What type of oil is typically used in a diesel engine turbocharger?
a) Vegetable oil
b) Hydraulic oil
c) Engine oil
d) Transmission fluid
c) Engine oil
Engine oil is used to lubricate and cool the turbocharger bearings,
which operate at very high speeds and temperatures.
3. What is the purpose of a flywheel in a diesel engine?
a) Store electrical energy
, b) Maintain engine momentum between power strokes
c) Filter engine oil
d) Increase air intake
b) Maintain engine momentum between power strokes
The flywheel smooths engine operation by storing rotational
energy, keeping the crankshaft turning smoothly between
combustion strokes.
4. What is the typical pressure range for a heavy equipment
hydraulic system?
a) 100–300 psi
b) 500–1000 psi
c) 2000–5000 psi
d) 6000–8000 psi
c) 2000–5000 psi
Heavy equipment hydraulics operate at high pressures to generate
sufficient force for lifting and moving loads.
5. Which component converts electrical energy into mechanical
energy in a starter motor?
a) Alternator
b) Solenoid
c) Armature
d) Battery
c) Armature
The armature rotates when current passes through it, producing
the mechanical motion needed to crank the engine.
6. What is the main purpose of a fuel injector in a diesel engine?
a) To filter fuel
, b) To atomize fuel for combustion
c) To increase fuel pressure in the tank
d) To control exhaust emissions
b) To atomize fuel for combustion
Fuel injectors spray fuel into the combustion chamber in a fine
mist, ensuring complete and efficient combustion.
7. Which type of brake system is most commonly used in modern
heavy equipment?
a) Mechanical drum brakes
b) Air-over-hydraulic brakes
c) Pure hydraulic brakes
d) Regenerative brakes
b) Air-over-hydraulic brakes
Air-over-hydraulic systems combine air pressure for activation and
hydraulic force for braking, providing powerful and reliable
stopping power.
8. What is the function of a differential in a heavy-duty vehicle?
a) Increase engine torque
b) Allow wheels to rotate at different speeds
c) Reduce fuel consumption
d) Act as a shock absorber
b) Allow wheels to rotate at different speeds
The differential ensures that wheels can rotate at different speeds
while turning, preventing tire wear and drivetrain stress.
9. What is the correct method to check for hydraulic fluid
contamination?
a) Visual inspection only
, b) Magnetic inspection
c) Sampling and laboratory analysis
d) Smelling the fluid
c) Sampling and laboratory analysis
Hydraulic fluid contamination can be microscopic; proper testing
ensures system reliability and prevents component damage.
10. Which system in heavy equipment controls engine
temperature?
a) Transmission system
b) Cooling system
c) Fuel system
d) Electrical system
b) Cooling system
The cooling system removes excess heat from the engine,
preventing overheating and maintaining efficiency.
11. What does the term “bleeding a hydraulic system” mean?
a) Draining all the fluid
b) Removing air trapped in the system
c) Replacing worn hoses
d) Adjusting fluid viscosity
b) Removing air trapped in the system
Air in a hydraulic system can cause spongy operation or loss of
function, so bleeding ensures proper fluid flow and pressure.
12. Which component regulates voltage in a heavy equipment
electrical system?
a) Starter
b) Solenoid
Certification Exam Questions And Correct
Answers (Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. What is the primary purpose of a torque converter in an
automatic transmission?
a) To increase engine horsepower
b) To allow the engine to continue running while the vehicle is
stationary
c) To reduce fuel consumption
d) To control vehicle steering
b) To allow the engine to continue running while the vehicle is
stationary
The torque converter transmits engine power to the transmission
while allowing the engine to idle without stalling.
2. What type of oil is typically used in a diesel engine turbocharger?
a) Vegetable oil
b) Hydraulic oil
c) Engine oil
d) Transmission fluid
c) Engine oil
Engine oil is used to lubricate and cool the turbocharger bearings,
which operate at very high speeds and temperatures.
3. What is the purpose of a flywheel in a diesel engine?
a) Store electrical energy
, b) Maintain engine momentum between power strokes
c) Filter engine oil
d) Increase air intake
b) Maintain engine momentum between power strokes
The flywheel smooths engine operation by storing rotational
energy, keeping the crankshaft turning smoothly between
combustion strokes.
4. What is the typical pressure range for a heavy equipment
hydraulic system?
a) 100–300 psi
b) 500–1000 psi
c) 2000–5000 psi
d) 6000–8000 psi
c) 2000–5000 psi
Heavy equipment hydraulics operate at high pressures to generate
sufficient force for lifting and moving loads.
5. Which component converts electrical energy into mechanical
energy in a starter motor?
a) Alternator
b) Solenoid
c) Armature
d) Battery
c) Armature
The armature rotates when current passes through it, producing
the mechanical motion needed to crank the engine.
6. What is the main purpose of a fuel injector in a diesel engine?
a) To filter fuel
, b) To atomize fuel for combustion
c) To increase fuel pressure in the tank
d) To control exhaust emissions
b) To atomize fuel for combustion
Fuel injectors spray fuel into the combustion chamber in a fine
mist, ensuring complete and efficient combustion.
7. Which type of brake system is most commonly used in modern
heavy equipment?
a) Mechanical drum brakes
b) Air-over-hydraulic brakes
c) Pure hydraulic brakes
d) Regenerative brakes
b) Air-over-hydraulic brakes
Air-over-hydraulic systems combine air pressure for activation and
hydraulic force for braking, providing powerful and reliable
stopping power.
8. What is the function of a differential in a heavy-duty vehicle?
a) Increase engine torque
b) Allow wheels to rotate at different speeds
c) Reduce fuel consumption
d) Act as a shock absorber
b) Allow wheels to rotate at different speeds
The differential ensures that wheels can rotate at different speeds
while turning, preventing tire wear and drivetrain stress.
9. What is the correct method to check for hydraulic fluid
contamination?
a) Visual inspection only
, b) Magnetic inspection
c) Sampling and laboratory analysis
d) Smelling the fluid
c) Sampling and laboratory analysis
Hydraulic fluid contamination can be microscopic; proper testing
ensures system reliability and prevents component damage.
10. Which system in heavy equipment controls engine
temperature?
a) Transmission system
b) Cooling system
c) Fuel system
d) Electrical system
b) Cooling system
The cooling system removes excess heat from the engine,
preventing overheating and maintaining efficiency.
11. What does the term “bleeding a hydraulic system” mean?
a) Draining all the fluid
b) Removing air trapped in the system
c) Replacing worn hoses
d) Adjusting fluid viscosity
b) Removing air trapped in the system
Air in a hydraulic system can cause spongy operation or loss of
function, so bleeding ensures proper fluid flow and pressure.
12. Which component regulates voltage in a heavy equipment
electrical system?
a) Starter
b) Solenoid
