ASE Medium-Heavy Truck Certifications 2 — Questions and Answers
Question 1: Which ASE Medium/Heavy Truck test covers diesel engine fuel and air induction systems?
- T1
- T2 (Correct answer)
- T4
- T6
Correct answer: T2
Test T2 covers diesel engines, including fuel, air induction, and exhaust systems.
Question 2: A technician must earn which credential to become an ASE Master Medium/Heavy Truck Technician?
- Pass T1 through T8 (Correct answer)
- Pass any five truck tests
- Pass T1 through T6
- Pass T2 and T4 only
Correct answer: Pass T1 through T8
Master Medium/Heavy Truck status requires passing all eight tests, T1 through T8.
Question 3: What is the primary purpose of a diesel engine's EGR system?
- Increase fuel pressure
- Reduce NOx emissions (Correct answer)
- Boost turbo speed
- Cool the transmission
Correct answer: Reduce NOx emissions
Exhaust gas recirculation lowers combustion temperature to reduce nitrogen oxide formation.
Question 4: On an air brake system, what component stores compressed air for service braking?
- Governor
- Air dryer
- Reservoir tank (Correct answer)
- Slack adjuster
Correct answer: Reservoir tank
Reservoir tanks hold the compressed air supply used to apply the brakes.
Question 5: Which test in the truck series addresses Electrical/Electronic Systems?
- T3
- T5
- T6 (Correct answer)
- T8
Correct answer: T6
Test T6 covers electrical and electronic systems on medium/heavy trucks.
Question 6: A driver reports the air dryer is cycling constantly. What is the most likely cause?
- A leaking air system (Correct answer)
- Low engine oil
- A bad alternator
- Worn brake shoes
Correct answer: A leaking air system
Constant compressor cycling and air dryer purging usually indicate an air leak depleting system pressure.
Question 7: What does the governor control on a truck air brake system?
- Brake chamber stroke
- Compressor cut-in and cut-out pressure (Correct answer)
- Trailer sway
- Steering effort
Correct answer: Compressor cut-in and cut-out pressure
The governor regulates the pressure at which the compressor loads and unloads.
ASE Medium-Heavy Truck Certifications 2
Which ASE Medium/Heavy Truck test covers diesel engine fuel and air induction systems?